II. 수생동물의 생리와 해부

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1 I. 수생동물과그생활환경 동물은그서식장소에따라수생동물 (aquatic animal) 과육생동물 (terrestrial animal) 로분류한다. 수생동물은스스로자기체온조절이불가능한변온동물로서, 환경의변화에매우민감하다. 따라서수의사는수생동물의질병을이해하고진료함에있어서, 동물의환경과정상적인생활상태에관한지식이꼭필요하다.

2 What is aquatic animal medicine? Aquatic animal medicine is a young specialty of veterinary medicine that includes medical care of marine mammals, sea turtles, fishes and aquatic invertebrates. There are broad sub-specialties within aquatic medicine which include care of captive marine mammals, care of pet fishes, zoo and aquarium species, aquaculture medicine, and clinical research involving free-ranging aquatic species. Specialty training incorporates aspects of clinical medicine, wildlife health, environmental science and engineering. Aquatic animal health specialization requires substantial training and experience beyond the four year veterinary degree, and may include graduate school, internships, and in some cases, residency training. Currently, there is a specialty certificate in aquatic medicine which can be earned through board certification by the American College of Zoological Medicine. There is also a certificate in fish pathology which can be earned through the American Fisheries Association.

3 What is aquatic animal? An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). Animals that move readily from water to land and vice versa are often referred to as amphibious. The term aquatic can in theory be applied to animals that live in either freshwater or saltwater. However, the adjective marine is most commonly used for animals that live in saltwater, i.e. in oceans, seas, etc. Aquatic animals (especially freshwater animals) are often of special concern to conservationists because of the fragility of their environments. Aquatic animals are subject to pressure from overfishing, destructive fishing, marine pollution and climate change.

4 나무에사는물고기도있다네 * - 서양서안홍수림서 ` 킬리피시 ` 발견 - 물고기가물을떠나나무에서사는일이가능할까. 나무에서사는물고기를물고기라불러야할지는의문이지만물과나무를오가며사는물고기가존재하는것은사실이다. 최근뉴사이언티스트지보도에따르면대서양서안맹그로브숲 ( 홍수림 ) 에서식하는한물고기는가뭄으로물이마르면습기가찬나무구멍속에들어가물이다시찰때까지몇달씩생존하는것으로나타났다. 이물고기는송사리과에속하는맹그로브킬리피시 ( 학명 Kryptolebias Marmoratus) 로평소에는홍수림의뿌리주변에고이는물웅덩이에살다가물이마르면썩은나무에나있는축축한벌레구멍속으로터전을옮긴다. 캐나다사이먼프레이저대학연구진에따르면이킬리피시는먹이와짝짓기에불리한환경속에서생존과번식을위해아가미를개조하고단성생식 (parthenogenesis; 자웅동체 hemaphrodite) 으로번식하는것으로전해졌다. 몸무게가 0.1g 에불과할정도로아주작은이물고기는지금까지발견된최초무성생식등뼈동물이다. 성체가된킬리피시는난정소라는생식기관을통해난자와정자를모두배출해체내에서자가수정하고체외로수정란을배출해어린성체를부화시키는방법으로종족을번식시키고있다. 이들킬리피시는마치콩깍지속의콩알처럼썩은나무속벌레구멍을가득채우며살아간다. 이들은평소물속에서는영역다툼을하지만나무속에살때는공격성이크게줄어서로최대한인내하며공존하는특성을보인다고연구진은밝혔다. 물밖에드러난나무에살게되면서이들의생리에도변화가생겼다. 캐나다겔프대학연구진은앞서킬리피시들이물과영양분을비축할수있도록아가미를개조하고질소폐기물을배출할수있도록피부에새로운단백질을형성한다는사실을발견했다. 이처럼극적인생리적변화과정속에서도이물고기들은비교적일정한대사율을유지하며물로돌아오면원래상태를회복하는것으로밝혀졌다. 킬리피시는브라질에서부터플로리다까지광범위한지역에서식하고있는데이들의무성생식방식이서식지개척에매우유리했기때문인것으로연구진은보고있다.

5 I-1. 수생동물의종류 1. 서식장소에의한구분 1) 담수동물 (fresh water animal) 하천, 호수, 온천등의담수역 ( 내수면이라고도함 ) 에서식하는동물 2) 기수동물 (brackish water animal) 담수와해수가섞여지는하구 (estuary) 나호수에서식하는동물 ( 숭어, 문절망둑, 바지락등 ) 3) 해수동물 (marine animal) 연안, 해양, 해저등해수중에서식하는동물

6 2. 생활양식에의한구분 1) 부유동물 (plankton) 수중에서서식하는동물성플랑크톤으로수류, 조류, 바람에의해 수동적으로이동하며생활 ( 연체, 환형, 절족동물의유생 ) 2) 유영동물 (nekton) 자신의운동기관으로자유롭게 ( 육상또는공 중도 ) 이동하며생활 ( 두족류, 갑각류, 어류, 양서류, 파충류, 수생조류, 수생포유류 ) 3) 저생동물 (benthos) 물밑바닥에서주로생활 ( 패류등 )

7 Plankton are any drifting organisms (animals, plants, archaea, or bacteria) that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification. They provide a crucial source of food to larger, more familiar aquatic organisms such as fish and whales Nekton refers to the aggregate of actively swimming aquatic organisms in a body of water (usually oceans or lakes) able to move independently of water currents. Nekton are contrasted with plankton which refers to the aggregate of passively floating, drifting, or somewhat motile organisms occurring in a body of water, primarily comprising tiny algae and bacteria, small eggs and larvae of marine organisms, and protozoa and other minute predators. Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.

8 3. 용도에의한구분 사람을중심으로한관점에서수생동물은유용, 무용, 유해한동물로구분되며, 유용한동물은다음과같이세분된다. 유용한동물중에도유해한동물이적지않으므로수생동물은공중위생학의중요한대상이다. 1) 식용동물사람에게동물성단백질을공급하는중요한식량자원 ( 조개, 게, 새우, 오징어, 해삼, 우렁쉥이, 각종어류, 개구리, 자라, 고래등 )

9 2) 애완 ( 관상 ) 용동물개인의취미에따라서사육이가능한수생동물 ( 비단잉어, 금붕어, 자라, 도마뱀등 ) 3) 전시용동물동물원이나수족관등에서관람을목적으로사육되는수생동물 ( 열대어나돌고래등모든수생동물이대상 ) 4) 장식품용동물장식용이나보석등으로가공사용되는수생동물 ( 진주조개, 전복, 악어등 ) 5) 유희용동물낚시와같이게임을목적으로이용되는수생동물 ( 붕어, 잉어, 연어등 )

10 6) 실험용동물생리실험, 약품의독성실험, 환경독성실험에사용되는수생동물 ( 개구리, 잉어, 송사리, 구피등 ) 7) 약용동물동양의학에서한약제조에사용되거나, 동물의특수성분을약품에 가공이용하는수생동물 ( 잉어, 자라, 미꾸라지, 거머리, 게등 )

11 ' 사람의각질을먹는다 ' 는 ' 닥터피시 ' 체험열기가찜질방, 테마파크, 온천뿐아니라카페에까지퍼진것. 닥터피시체험장을설치한업체들은 " 각질제거, 마사지효과는물론아토피성피부염 (atopic dermatitis) 이나건선 (psoriasis) 등의피부질환에효능이있다 " 고대대적으로홍보하고있다. ' 닥터피시 ' 는 37 의온천에서서식하는잉어과의물고기. 터키터어키의캉갈온천에서식하는 ' 캉갈피시 ( 학명가라루파 Garrarufa)' 를일컫는다. 물속에서사람의피부를핥는짓을통해아토피등피부질환을치료한다고해서 ' 닥터피시 ( 의사물고기 )' 로불리게됐다. 현재독일, 오스트리아, 스위스등에서대체의학용으로쓰인다하지만국내에들어와있는 ' 닥터피시 ' 는대부분 ' 중국산짝퉁 ' 으로중국의친친어 ( 親親魚 ' 뽀뽀하는물고기 ' 라는뜻 ) 다. " 친친어는의학적으로효능이검증된바가전혀없고, 유럽어느나라에서도피부테라피에사용하지않는다 " 며 " 닥터피시는오직캉갈피시한종뿐 " 이라고말했다. 업체들이친친어를닥터피시로소개하면서 ' 아토피등피부질환을치료한다 ' 고홍보하는것은명백한과장광고라는주장이다. 캉갈피시는잉어과에속하고, 친친어는농어목시클리드과에해당한다. 캉갈피시는빨판형의입을통해피부를빨아먹지만, 친친어는돌출된형태의입으로피부를쪼아서각질을먹는다. 대다수전문가들은닥터피시의치료효능에의문을표시한다. 물의상태가청결하지못한경우물고기가각질을뜯어먹는과정에서상처가생기면그상처에세균에오염된물이들어가치료는커녕병만얻게될수있다 " 고했다. ( 조선일보 ; ) 터키산캉갈피시 ( 위 ) 와중국산친친어. / 닥터피시주식회사제공

12 기뢰찾기특수임무 ` 척척 ` 돌고래 바다사자쇼만하는줄알았더니 미해군서 100 마리훈련기뢰찾으면초음파보내 미국이지난 30 년동안수중기뢰 (submarine mine) 를찾는데돌고래와바다사자등해양동물을투입해상당한성과를거뒀다고 AP 통신이 13 일보도했다. 미해군은특히돌고래와바다사자를여러전투에투입해큰재미를봤으며, 현재샌디에이고의포인트로마기지에서만돌고래 75 마리, 바다사자 25 마리를훈련시키고있는것으로알려졌다. 돌고래와바다사자는수중에서후각. 청각. 시각이모두뛰어나기뢰찾기에제격이다. 특히사람은물론로봇조차들어가활동하기힘든수심 200m 까지잠수할수있다. 통신에따르면기뢰를찾도록동물을훈련하는일은생각보다간단하다. 동물에게기뢰를보여줄때마다먹이를준다. 그러면동물은다시먹이를얻을기대감으로수중에서기뢰를찾아낸다. 이런훈련을반복적으로받은동물은기뢰를발견하면특이한초음파를보내게된다. 그러면군인들이바다위선박이나수중잠수함에서특수장비로이초음파를포착해수뢰위치를확인하는것이다. 돌고래의경우지능지수 (IQ) 가 70~90 으로인간으로치면다섯살아이와비슷할정도로머리가좋다. ( 중앙일보, )

13 영화속한장면? 어린이들태워주는돌고래화제 어린이들을태워주는야생돌고래가화제가되고있다고 8 일뉴질랜드언론들이보도했다. 수영을즐기는어린이들사이에돌고래한마리가함께있다. 아이들을태우고수영을하기도한다. 현지 TV 가 디즈니여름블록버스터의한장면같다 고평한이이색적인장면의주인공은모코라는이름의돌고래. 뉴질랜드기즈번남쪽에있는마히아의해변에나타난이돌고래는작년 8 월부터목격되기시작했다. 올여름돌아온모코는더욱친절하고사교적이다. 어린이들은물론어른들과도서로껴안은채수영을즐기는돌고래모코는지역신문및방송등에소개되었으며많은관광객들이돌고래를보기위해이지역을찾고있다고언론은전했다. 돌고래와함께수영을즐긴경험을한지역주민및관광객들은 돌고래가너무나사랑스럽다 면서놀라움을표시했다. 돌고래가사람을위해자신의등을내주기도하며, 지느러미를잡은채수영을할수도있다는것이지역주민의설명. 또모코가사람들이주는먹이도잘받아먹고있다고언론은덧붙였다. 과학자들은이런일이대단히희소하다고평했다. 그러나일부동물전문가들은이돌고래가공격적으로변하거나질병을옮길수도있다며주의를당부했다. ( 사진 : 천사돌고래 모코 의모습 / 뉴질랜드언론보도화면 )

14 4. 계통분류학에의한구분

15 * 동물의계통수 (dendrogram)*

16 Domains of Life For many years, living organisms were divided into two kingdoms: Animalia (animal) and Plantae (vegetable). In the 1800s, scientists realized these two kingdoms could not adequately express the diversity of life. Since the 1960s, the most widely used scheme for classifying life consists of five kingdoms. This "kingdom scheme" has co-existed with another classification of living organisms based on cell complexity: Eukaryotes: Complex cells with organized structures inside called "organelles" (e.g., nuclei, mitochondria, chloroplasts). Protists, Fungi, Plants, and Animals are examples Prokaryotes: Simple cells without organelles. Bacteria, for example Recent studies have shown that bacteria are far more diverse than previously thought. Thus Prokaryotes are now divided into two domains: Bacteria and Archaea; these are as different from each other as either is from the Eukaryotes. Viruses are fourth group of biological entities, although not organisms in the same sense as Eukaryotes, Archaeans, and Bacteria. However, they are of considerable biological importance and, like bacteria, help cycle organic matter in the marine food web.

17 The Classification of animals The science of classifying organisms is called taxonomy. In order to study living things, scientists classify each organism according to its: Kingdom-Phylum-Class-Order-Family-Genus-Species In biology, kingdom is a taxonomic rank, which is either the highest rank or in the more recent three-domain system, the rank below domain. Kingdoms are divided into smaller groups called phyla (in zoology) or divisions in botany. The complete sequence of ranks is life, domain, kingdom, phylum, class, order, family, genus, and species. Currently, textbooks from the United States use a system of six kingdoms (Animalia, Plantae, Fungi, Protista, Archaea, Bacteria). British textbooks may describe five kingdoms (Animalia, Plantae, Fungi, Protista, and Prokaryota or Monera).

18 1. Kingdom 1) Animalia ; which is made up of animals 2) Plantae ; which is made up of plants 3) Protista ; which is made up of protists (single-celled creatures invisible to the human eye) 4) Fungi ; which is made up of mushrooms, mold, yeast, lichen, etc 5) Monera : which is made up of the three types of bacteria 2. Phylum - Kingdom Animalia 1) Chordata ; which contains all animals with backbones (fish, birds, mammals, reptiles, amphibians) 2) Arthropoda ; insects, spiders, crustaceans 3) Mollusca ; snails, squid, clam 4) Annelida ; segmented worms 5) Echinodermata ; starfish, sea urchin 3. Class Phylum Chordata 1) Aves (birds) 2) Reptilia (reptiles) 3) Amphibia (amphibians) 4) Mammalia (mammals) and several others. 4. Order - Class Mammalia - Rodentia (mice, rats), Primates (Old- and New-World monkeys), Chiroptera (bats), Insectivora (shrews, moles), Carnivora (dogs, cats, weasels), Perissodactyla (horses, zebras), Artiodactyla (cows), Proboscidea (elephants) and many more. 5. Families - Order Carnivora - Canidae (dogs), Felidae (cats), Ursidae (bears), Hyaenidae (hyaenas, aardwolves), Mustelidae (weasels, wolverines), and many more. 6. Genus - Family Felidae - Acinonyx (cheetah), Panthera (lion, tiger), Neofelis (clouded leopard) and Felis (domestic cats). 7. Species - Genus Panthera - Panthera leo (lion) and Panthera tigris (tiger).

19 The kingdom Animalia contains approximately forty phyla. The largest and most commonly studied phyla of animals are: 1) Porifera (sponges) 2) Cnidaria (jellyfish, hydras, sea anemones, Portuguese man-of-wars, and corals) 3) Platyhelminthes (flatworms, including planaria, flukes, and tapeworms) 4) Nematoda (roundworms, including rotifers and nematodes) 5) Mollusca (mollusks, including bivalves, snails and slugs, and octopuses and squids) 6) Annelida (segmented worms, including earthworms, leeches, and marine worms) 7) Echinodermata (including sea stars, sea cucumbers, sand dollars, and sea urchins) 8) Arthropods (including arachnids, crustaceans, millipedes, centipedes, and insects) 9) Chordata (animals with nerve chords - this group includes the vertebrates)

20 Kingdom Nr. of species Bacteria... 4,000 Protoctists (algae, protozoa, etc)... 80,000 Animals, vertebrates... 52,000 Animals, invertebrates... 1,272,000 Fungi... 72,000 Plants ,000 Total number of described species... 1,750,000 Possible nr. with unknown species: 14,000,000 from the United Nations publication: UNEP-WCMC (2000). Global Biodiversity: Earth's living resources in the 21st century. Cambridge, World Conservation Press.

21 Nomenclature, classification and identification In biological science, at least, nomenclature is regarded as a part of taxonomy. Taxonomy can be defined as the study of classification including its principles, procedures and rules, while classification itself is the ordering of taxa (the objects of classification) into groups based on similarities and/or differences. Doing taxonomy entails identifying, describing and naming taxa so nomenclature, in this strict scientific sense, is that branch of taxonomy concerned with the application of scientific names to taxa, based on a particular classification scheme and in accordance with agreed international rules and conventions. Identification determines whether a particular taxon (singular of taxa) is identical to another one that has already been classified and named so classification must precede identification. As taxa are rarely strictly identical, but only treated as such for the purposes of the classification, this procedure is sometimes referred to as determination". The formal system of naming species of living things is called binomial nomenclature (especially in botany, but also used by zoologists), binominal nomenclature (since 1953 the technically correct form in zoology), or binary nomenclature. This system of naming was invented by Linnaeus. The up-to-date version of the rules of naming for animals and plants are laid out in the International Code of Zoological Nomenclature and the International Code of Botanical Nomenclature respectively. The essence of the binomial system of naming is this: each species name has two parts, the genus name and the species name (also known as the specific epithet), for example, Homo sapiens, which is the scientific name of the human species. Every two-part scientific name is either formed out of (modern scientific) Latin or is a Latinized version of words from other languages.

22 1) Protozoa (phyla: protozoa) Protozoa are simple, single-celled animals. They are the smallest of all animals. Most protozoa are microscopic in size, and can only be seen under a microscope. However, they do breathe, move and reproduce like multicelled animals. There are several types of protozoa. The amoebas are clear, shapeless cells. Flagellates have a body shape looking like a hair. Although we can't see them, protozoa do a lot for us. Protozoa play a useful role in the food chain as a source of food for fish and other animals. Some protozoa are helpful to humans by eating dangerous bacteria. Unfortunately, other protozoa are parasites and can be harmful to humans by transmitting disease. Protozoa eat tiny algae and bacteria. Some protozoa absorb food through their cell membrane. Others surround and engulf their food or have openings to collect food. They digest their food in stomach-like compartments called vacuoles. Protozoa take in oxygen and give off carbon dioxide through the cell membrane. Protozoa reproduces by splitting in half.

23 1) 무척추동물 (invertebrate) 1. 원생동물원생동물문 Protozoa : 단일세포로구성 - 편모충강 (flagella), 육질강 (amoeba), 포자충강 (sporozoa), 섬모충강 (cilia) 2. 해면동물해면동물문 Porifera : 최하등의후생동물, 고착성, 방사상대칭

24 1) 해면동물문 (Phylum Porifera) - 해면 ( 여과섭식자, 암수한몸, 운동성없음 ) 몸은원통형이고, 위강 (spongocoel) : 중심강 (central cavity) 이있으며, 끝에대공 (osculum) 이있다. 소공세포 (porocyte) : 물을위강으로들어가게하는역할위층 ( 안쪽벽 ) 은편모를갖는동정세포 (choanocyte, collarcell) 로되어있다. 수류를일으켜바닷물을소공세포로들어오게함 ( 물 : 산소와먹이제공 ) 동정세포 : 소공세포를통해들어온물을점액성분비물을통해유기물포획 식세포작용 (phagocytosis) 을통해유입 식포 (food vacuole) 속에서소화

25 3. 강장동물, 유즐동물 a. 강장동물문 Coelenterata : 정형의조직, 기관과소화강을갖는진정후생동물 (Eumetazoa). 고착성인폴립 (polyp ; 산호, 말미잘 ) 과유영성이며양성생식을하는해파리 (medusa) 가있다. - 히드로충강 ( 해파리 ), 발충강, 화충강 ( 말미잘, 산호 ) b. 유즐동물문 Ctenophora : 2 축의방사상대칭의삼배엽성동물 (sea gooseberry)

26 * Cnidarians (corals, anemones, jellyfish) *

27 TISSUES AND THE RADIAL PLAN PHYLA CNIDARIA AND CTENOPHORA 후생동물 - 좌우대칭또는방사대칭 (1) 자포동물문 ( 강장동물문으로분류 ; Phylum Cnidaria) - 둬은막으로된동물히드로충류, 해파리류, 산호충류, 말미잘등이포함대부분조직단계로구성 ( 기관 - 촉수 ) 되어있으나몇몇은기관을가지고있다. 대부분종의촉수는자세포 (cnidocyte; 자포 (nematocyst) 발사 ) 라는쏘는세포로무장위수강 (gastrovasoular cavity) : 주머니모양의장으로소화와순환기능수행신경계는중심화하지못해신경망 (nerve net) 형태 ( 신경전도는일방통행 ) 감각세포로부터충격을받으면수축세포와자세포에전하여반응성체 : 폴립형 (polyp) - 고착성, 메두사형 (medusa) - 헤엄쳐다님 일부자포동물에서는폴립형과메두사형이세대교번중나타남 ( 모두 2 배체 - 식물세대교번과의차이점 ) 1 히드로충강 (Class Hydrozoa) : 히드라 ( 무성출아로생식, 유성생식은상황이나쁠때만 ) 대부분폴립상태이며조밀한군체형성출아에의한무성생식 ( 일부폴립들은유성생식에특수화되어정자와난자를형성하는메두사형을만듬 ) 섬모운동에의해먹이흡수히드라 : 꽃병과간은모양으로개체상태이며, 몽이대단히작고가늘며, 대부분길이가 3cm, 메두사형단계와플라눌라유생단계가없다.

28 2 해파리강 (Class Scyphozoa) 대부분유영의메두사형단계이며, 생활사는히드로충류와반대몸이종모양이고촉수로둘러싸여있으며, 밑면중앙에입이있다. 보통떠다니지만근육섬유의수축에의해유영도할수있음암수딴몸이며체외수정 유영하는플라눌라유생이발달되면곧바다바닥의암석에착성하게되고, 히드라와비슷한작은폴립인스키피스토마 (scyphistoma) 로변함 스피키스토마가계속분열하여어린해파리방출 3 산호충강 (Class Anthozoa) : 산호, 말미잘 폴림형, 출아에의한무성생식으로새로운폴립생성 cf. 유성생식 - 암컷과수컷폴립이각각정자, 난자를만들어물속에서수정 접합체는유영성풀라눌라로발달산호 : 촉수로먹이를섭취할수있었으나대부분열대산호는광합성공생조류가영양공급 (2) 유즐동물문 (Phylum Ctenophora) - 빗해파리류 방사대칭이며발광성생물 - 자세포가없다. 자포동물과달리섬모가함쳐져만들어진 8 줄의즐판대 (comb row; 운동성부여 ) 를가짐촉수에는자세포대신아교세포 (glue cell) 로무장 먹이를유혹해함정에빠뜨림

29 4. 편형동물, 중생동물 a. 편형동물문 Platyhelminthes : 좌우대칭, 두부분화, 중배엽의기관 - 와충강, 흡충강 (flukes), 조충강 (tapeworms) b. 중생동물문 Mesozoa 5. 유형동물, 곡형동물, 부형동물 a. 유형동물문 Nemertinea : 좌우대칭의긴띠모양, 관상의소화관, 자웅이체 b. 곡형동물문 Kamptoza : 해저에착생하는소태상동물 c. 부형동물문 Aschelminthes : 좌우대칭, 원통형또는실모양 - 윤형강 (rotifers), 복모강, 선형강 (round worms), 유선형강, 동문강, 새예강, 구두강 (spiny-headed worms)

30 2) Annelids (phyla: Annelida); worms and leeches There are about 9,000 species of Annelids known today, including worms and leeches. They can be found almost anywhere in the world. Annelids have existed on Earth for over 120 million years. Annelids have bodies that are divided into segments. They have very well-developed internal organs. One common characteristic of annelids is that they don't have any limbs. Some annelids may have long bristles. Others have shorter bristles and seem smooth, like the earthworm shown here. There are many types of worms. Commonly known worms include earthworms, roundworms and flatworms. Most worms are small, measuring fractions of an inch to several inches long. Other worms, such as the ribbon worm, can grow up to 100 feet in length. Some worms are considered parasites, in that they live inside the human body.

31 BODY CAVITIES, A ONE-WAY GUT, AND PHYLA NEMATODA AND ROTIFERA 대부분의동물들은좌우대칭으로의전화와함께두화 (cephalization; 동물들이머리와꼬리부분을갖추게됨, 머리부근의끝은음식물, 빛, 소리등의자극을감지하기위한감각구조장치 신경세포들이머리끝에집중되고뇌의진화는가속화 ) 경향을갖음 (1) 3 배엽의배 (Three-Layered Embryo) 자포동물과유즐동물을제외한모든후생동물은중배엽 (mesoderm) 을갖음 (3 배엽동물 ) 3 배엽 : 외배엽 - 신경계의기원내배엽 - 분비선, 장, 혈관등의안족벽과호흡생식계안쪽벽의기원중배엽 - 근육형성, 척추동물에서는내골격과혈액형성에관여 (2) 편형동물문 (Phylum Platyhelminthes) - 편형동물좌우대칭 앞쪽끝과뒤쪽끝이있다. 몇개의기관계를갖는다. 3 배엽동물에는중배엽에서기원한조직에근육과그와연합된유조직세포 (parenchyma cell) 가있다. 호흡계와순환계가없다 ( 대부분의세포들이몸표면에근접해있어대상필요한충분한가스가세포사이로쉽게확산 ) 기생성종들은신경계와소화계가거의퇴화했거나존재하지않음다른 3 배엽동물과달리장과체벽사이에내부강소가없다 무체강동물

32 1 와충강 (Class Turbellaria) : 자유생활편형동물 ex) 플라나리아 (planaria Dugesia) 기관계발달, 신경계는중심화집중화현상 앞쪽끝에집중되어커다란신경절 (gangia) 과안점 (eyesport) 이있다. 두개의복신경 (ventral nerve) 이몸의길이를따라뻗어있고수많은작은신경절로부터나온가지들이사다리같이배열포식자이며부식성동물 점액질층에먹이를가두고근육질의인두 (pharynx) 로섭식 위수강속에서소화되기도하고, 식세포작용을통해소화되기도함원신관 (protonephridium) - 민물산편형동물의삼투조절 ( 몸속의물과이온의평형유지 ) 을담당하는불꽃세포계암수한몸이며무성생식과유성생식방법모두사용플라나리아는작은성체로직접발생하지만, 많은해산와충류는성모난유생단계를거친다.

33 2 흡충강 (Class Trematoda) : 흠충기생성이며섬모가없고, 위수강이분지되지않아관모양의두부분으로나뉨흡반 ( 구흡반, 복흡반 ) 은숙주의조직에부착할때사용많은종류의동물에침입하여아가미, 허파, 간, 소화관등여러부분에그들의집마련간흡충 (Chlonorchis inensis) 의생활사 1. 사람 : 유성생식에의해미라시디아 (miracidia) 를품는알집발생 미라시다아는배설물을통해 1 차숙주를떠남 배설물을먹은달팽이감염 2. 달팽이 : 스포로시스트 (sporocyst) 형성 무성생식에의해수많은레디아 (redia) 형성 헤엄칠수있는세르카리아 (cercaria) 형성 물고기에부착 3. 물고기 : 근육속에구멍을파고들어가포낭형성 1 착숙주가물고기를먹음 메타세르카리아 (metacercaria) 가창자에서부화 간으로 ( 생활사반복 ) 3 촌충강 (Class Cestoda) : 촌충소화강이없으며체벽을통해숙주의소화된음식을직접흡수 ( 촌충류의가장바깥막은고도의주름으로되어있어표면적을넓게한다 ) 숙주동물에큰해를주지않음편절 (proglottid) : 출아법을통해생성완전한생식단위로난소, 정소그리고수컷과암컷의교접기구모두보유교차수정과편절간의자가수정또는편절내자기수정도발생

34 (3) 유형동물문 (Phylum Nemertina, Thynchocoela) - 유형동물자유생활을하느해산포식자내부에체강이없으며 ( 무체강동물 ) 몸에섬모가있다. 삼투조절에불꽃세포이동한쪽에는입을그리고다른한쪽에는항문을갖는작은관과같은장 (gut) 을갖는다. 체강과한방향의장 ( 두번째진화적발달 ) - 선형동물과윤형동물문한방향으로잘발달 : 입, 장, 항문을갖는소화관을갖춤 ( 장이체벽내에있기때문 ) 체강동물 (coelomate) : 체강 (coelom; 관들사이의공간 ) 이있는동물진체강 - 중배엽으로부터유래된조직으로싸여있으며, 이조직을복막 (peritoneum) 이라함의체강 (pseudocoelom) - 몸속의강소가부분적으로만중배엽성조직과접해있는경우 ex) 선형동물문, 윤형동물문

35 (1) 선형동물문 (Phylum Nematoda)- 회충, 선모충 좌우대칭, 뚜렷한머리는없고몸은유연성있는강한각피로둘러싸임유체골격 (hydrostatic skeleton) : 액체로채워진의체강으로동물의형태를유지시켜고착근육운동을위한지지체역할을한다. 1 회충 : 돼지와사람이숙주이며암수딴몸, 중간숙주는없다. 가늘고원통형이며통상양쪽끝이더욱가늘다. 숙주의장에서기생하며알은배설물을통해밖으로나감 유생은작은창자에서부화 창자벽을통해혈류를타게됨단백질소화효소인트립신을중화할수있어장속에서생존가능 2 선모충 : 돼지, 집쥐, 사람이숙주오염된고기에의해감염 포낭으로된유생은창자의벽에구멍을파고그곳에서성숙생식 림프경로를통해이주 (2) 윤형동물문 (Phylum Rotifera) 기생성이아니다. 머리부근에있는두쌍의섬모환을사용하여섭식 식도나모래주머니속에서잘게부서진다. 원신관을갖는다 진짜배설계를형성하여질소노폐물을배설하고삼투조절의문제를해결한다. 유성생식하는윤형동물의암컷 무성생식으로여러세대를거침 ( 단위생식 ) 난은감수분열하지않기때문에 2 배체로존재 2 배체의알이분열하여많은암컷발생환경의자극 : 감수분열에의해반수체난형성 수정되지않을경우수컷발생 반수체난과정자수정 두껍고저항력강한접합자형성 환경이적당해지면암컷으로발생 수컷역할은단순하지만가끔일어나는유전자유입을통해집단의유전적다양성부가

36 6. 환형동물환형동물문 Annelida : 체절구조 (metamerism), 중배엽상피의진정체강, 근육, 신경, 순환, 배출, 생식계를가짐, 자웅이체의난생 - 원시환충강, 다모강 ( 갯지렁이 ; lugworm), 빈모강 (common earthworm), 거머리강 (leeches), 흡구충강 7. 성구동물, 촉수동물 a. 성구동물문 Sipunculoidea : 좌우대칭의원통형, 바다에서식 b. 촉수동물문 Tentaculata : 촉수가있는구상돌기, 3 등분된체강 8. 여러가지소동물 a. 모악동물문 Chaetogonatha : 소형, 원통형의해산부유동물 b. 반색동물문 Hemichordata : 원통형의 3 등분된좌우대칭구조를갖는저상동물 c. 유조동물문 Onychophora : 간단한눈과촉각을가짐 d. 완보동물문 Tardigrada : 통상수생의현미경적동물방추형 e. 설형동물문 Pentastomida : 포유류나파충류의기생동물

37 구더기 거머리 난치병해결사 귀한몸 구더기 돼지의편충 거머리 물고기등생물체를이용한치료법이현대의학에서부상하고있다. 민간요법이나고대의술에서쓰이다그효과가검증된데따른것이다. 일부온천에서도입해널리알려진잉어과물고기 닥터피시 (Doctor Fish) 로건선 ( 乾癬 ) 같은피부병을치료하는것이대표적인사례다. 구더기세균에감염된지저분한상처를치료하는 구더기요법 은전세계적으로 2000 여의료기관에서시행되고있다. 국내에서는최근 10 여개의대학병원이이를도입했다. 구더기는파리의알에서나오는유충 ( 幼蟲 ) 으로길이는 0.5~1 cm이다. 구더기는침에서생체조직을녹이는효소를갖고있는데, 이를분비하여생체를녹이고입안의강력한펌프로빨아들인다. 이과정을통해구더기가상처에있는세균물질을삼키고새살을돋게한다. 구더기한마리는 0.3g 에해당하는상처의고름과죽은살을 5 분안에없앨수있다. 분당서울대병원성형외과허찬영교수팀이수술로제거할수없는지저분한상처가있는환자 11 명에게구더기요법을실시한결과, 5 명의상처가깨끗이아무는효과를봤다. 허교수는 중풍환자처럼오랫동안누워있어엉덩이이짓물러생기는욕창을회복시키는데구더기요법이제격 이라고말했다 돼지의편충약물로잘낫지않는대장염치료를위해돼지의편충 ( 기생충의일종 ) 을이용한치료법연구는미국과독일등에서활발히이뤄지고있다. 국내에서도의료용편충알이곧수입될예정이다.

38 미국아이오와대의대데이비드엘리어트교수팀은난치성장염을앓고있는환자 54 명을두그룹으로나눠한쪽에는돼지의편충알을 2 주간격으로 12 주간대장에투여하고, 다른그룹에는가짜약을투여했다. 그결과편충알을투여받은환자의대장염이씻은듯이나았다.. 그의이론에따르면, 선진국에서급증하고있는장염이나 크론씨병 ( 소장과대장에만성적인염증과궤양이생겨구멍이뚫리는희귀질환 ) 은몸속기생충이박멸된데따른결과라는것이다. 사람의장속에는어느정도의편충이살고있어서대장염등질병에대한면역력을키우도록돕고있는데, 기생충이사라지면서덩달아문제가생겼다는주장이다. 이런이론을바탕으로 오버메드 라는독일계회사에서돼지편충알을의약품으로생산하고있다. 거머리우리나라에서한해 2 만 ~3 만마리의거머리가소비될정도로의료계에서거머리는상한가를기록하고있다. 성형외과학회에서거머리요법연구논문도속속등장하고있다. 거머리는 2004 년미국 FDA 승인을받은정식 의료용물질 이다. 거머리는주로손가락절단후접합부위를자연스레낫게하는데쓰인다. 손가락끝마디가사고등으로절단되면현미경을보면서동맥을이을수있으나, 정맥은쪼그라들어이을수없다. 이렇게되면접합된손가락에피가고여퉁퉁붓는다. 그래서고안해낸것이피를빠는거머리요법. 이요법을약 1 주일간매일하면손가락혈액순환이이뤄지고그사이새로운정맥이생겨나접합수술성공률이올라간다. 거머리침의 히루딘 이라는물질은피를잘빨게하고상처도아물게한다. 거머리요법을당뇨병때문에생긴발궤양등에쓰고있는한동하 ( 한의사 ) 원장은 처음엔환자들이징그럽게생각하지만한번효과를보면태도가달라진다 라고말했다

39 의료용생물체가격은 영국산의료용거머리, 마리당 2 만 5000 원구더기 200~250 마리담긴주머니 20 만원 구더기 거머리등을이용한치료가활발해지면서의료용생물체시장도점차커지고있다. 구더기는현재전국 10 여개대학병원에서수술이나약물로낫지않는지저분한상처치료에쓰인다. 구더기는 1 회용녹차를담은 티백 처럼망사형주머니 ( 바이오백 ) 에담겨공급된다. 크기 4 4 cm주머니에 마리의구더기가들어간다. 이주머니를상처부위에붙이면구더기가망사사이로상처부위를핥아먹는다. 주머니하나의값은 20 만원선. 국내에의료용구더기를공급하는 바이오몬드코리아 사 ( 社 ) 에따르면매달 15 개의바이오백이팔려나간다. 회사는구더기주문이늘자무균구더기바이오백생산기술을독일로부터도입해작년부터본격국내생산해왔다. 과거에는구더기를상처부위에풀어놨으나관리하기가힘들어 바이오백 시스템이개발됐다. 이회사는난치성장염치료에쓰이는 돼지편충알 (TSO) 도수입할예정이다. 의료용거머리는국내에서한해 3 만 ~4 만마리가소비되고있다. 거의대부분이영국산이다. 국산참거머리는크기가작아피를빠는힘이약하기때문에덩치가 2 배이상인영국산 ( 최대길이 8 9 cm ) 을쓴다. 한마리당가격은 2 만 5000 원선이다. 하루한번치료에통상 2~4 마리의거머리가쓰인다.

40 THE COELOM AND COELOMATES ; 체강 (coelom) a. 중배엽에서유래된단단한복막 (peritoneu) 으로싸여있으며, 복막으로부터주름잡힌장간막 (mesentery) 이형성 장간막 : 기관들을고정시키는역할 기관들이체강속에서어느정도움직일수있게해줌 b. 순환계가있는종에서는혈관이장간막을통과하면서소화관에혈액운반 c. 유체골격형성 : 체강속의액체에대항해서생기는근육의압력이몸을단단하게하고, 구멍을팔수있게한다.

41 9. 연체동물연체동물문 Mollusca : 좌우대칭의두부와몸통으로나뉨. 족부 (foot) 가발달. 체표는여러층의각 (shell) 으로구성, 자웅이체로대부분난생 - 다판강, 구복강, 단판강, 복족강 ( 소라고둥, 우렁이등의권패류 ), 굴족강, 이매패강 (bivalves ; 대합, 홍합, 굴, 가리비등의일반패류 ), 두족강 ( 갑오징어, 오징어, 낙지, 문어등 )

42 3) Mollusks (phyla: Mollusca) Mollusks were among the first inhabitants of the Earth. Fossils of mollusks have been found in rocks and date back over 500 million years. Mollusk fossils are usually well preserved because of their hard shell. Most mollusks have a soft, skin-like organ covered with a hard outside shell. Some mollusks live on land, such as the snail and slug. Other mollusks live in water, such as the oyster, mussel, clam, squid and octopus. Land living mollusks, like the snail, move slowly on a flat sole called a foot. Ocean living mollusks move or swim by jet propulsion. They propel themselves by ejecting water from their body. For example, the squid ejects water from a cavity within its body, and the scallop ejects water to move by clamping its shell closed. Other ocean living mollusks, like the oyster, attach themselves to rocks or other surfaces, and can't move. They feed by filtering small food particles from water that flows through them.

43 10. 절지동물절지동물문 Arthropoda : 서로다른모양의체절구조로, 두부, 흉부, 복부로나뉨. 소화관은전장, 중장, 후장으로되어있고, 자웅이체의체내수정. 난생또는난태생. 키틴질의외골격. 동물중가장종류가많음 - 삼엽충강 ( 화석 ), 갑각강 ( 가재류, 물벼룩, 물이, 크릴, 새우류, 게류 ), 곤충강 (insect), 순각강, 배각강, 소각강, 결합강, 절구강 (horseshoe crab), 거미강, 바다거미강

44 4) Arthropods (phyla: Arthropoda) Arthropods make up over 75% of the world's animal species. Arthropods include animals such as insects, crustaceans and arachnids. The largest group of Arthropods is the insects. The next largest group is the crustaceans, including lobsters and crabs. The arachnids include spiders and ticks. Other Arthropods include centipedes and millipedes. Arthropods have limbs with joints that allow them to move. They also have an exoskeleton, which is a hard, external skeleton. Their body cavity contains the nervous system, circulatory system, reproductive system and digestive system.

45 한국강태공들이남극생태계망치는주범이라뇨? 환경운동연합은 지구온난화와남극생태계의위기 를주제로한토론회에서한국의낚시인들이남극의생태계를위협하고있다는주장을폈다. 또토론회전날에는서울시청앞광장에서펭귄고래등남극생물의모형을쓰고낚시꾼에게크릴사용중단을호소하는퍼포먼스를펼치기도했다. 한국이남극에서연간 4 만 t 정도를잡아서 2004 년과 2005 년어획량이세계 1 위였으며이들대부분이낚시용미끼로쓰이고있으니꾼들이자제해달라는것이다. 크릴은전세계에 50 여종, 남극에 20 여종이서식하고있는난바다곤쟁이과에속하는플랑크톤. 새우와모양이비슷해 크릴새우 라고부르는이들도있으나엄밀히말하면고등한동물성플랑크톤이다. 이끼류와식물성플랑크톤 - 크릴 - 오징어류로이어지는남극의먹이사슬에서크릴이차지하는비중은매우높다. 총자원량이 5 억 t 에이른다고하지만지구온난화의위협을생각한다면조심스러운접근이필요한것이사실이다. 크릴은주로물고기양식과향료생산, 낚시용으로소비하고연구용으로도상당량을쓰고있다. 크릴이낚시미끼로인기가높은것은아미노산이풍부하게함유돼있기때문. 낚시뿐아니라부시리나방어, 참돔어업용미끼로폭넓게쓰이고있다. ( 조선일보 ; )

46 11. 극피동물극피동물문 Echinodermata : 두부와체절구조가없는방사상모양 (five-rayed radical symmetry) 의저착성해산동물 - 불가사리강 (star fishes), 거미불가사리강, 성게강 (sea urchins), 해삼강 (sea cucumber) 12. 원삭동물원삭동물문 Protochordata : 착생, 부유또는매몰생활을하는척삭 (notochord) 을갖는후구동물. 새열 (gill slit) 이있는새강 (branchial cavity) 을가짐 - 미삭강 ( 우렁쉥이, 미더덕 ), 두삭강 ( 창고기 )

47 5) Echinoderms (phyla: Echinodermata); starfish, sea urchin and family Echinoderms are marine animals that live in the ocean. Common echinoderms include the sea star, sea urchin, sand dollar and sea cucumber. Most echinoderms have arms or spines that radiate from the center of their body. The central body contains their organs, and their mouth for feeding. Sea stars, commonly known as the starfish, have 5 or more arms attached to their body. On the bottom of the Starfish are small tube feet to help with movement and feeding. The starfish's mouth is underneath, and is capable of eating other sea life such as clams and mussels. Another type of echinoderm is the sea urchin. Sea urchins have many spines connected to their body. These spines help to protect them from predators.

48 PROTOCHORDATA ( 원삭동물문 )- 미삭동물, 두삭동물 a. 새열 (gill slit) 이있다 ( 원시척색동물 - 먹이섭취, 어류 - 새열사이의새궁 (gill arch) 이아가미지지, 이외척추동물 - 발생중내에서만나타남 ) b. 등쪽에속이빈신경삭 (nerve cord; 척삭 notochord 이라는연골성구조 ) 을가진다. c. 항문뒤쪽에꼬리가있다. 모든척삭동물은적어도발생중어느한시기에척삭을갖는다. d. 척삭 (notochord) : 등뒤쪽에있으며유연골격지지체역할 e. 현존척삭동물에서는발생중의배나유생에서만나타나고, 척추동물에서는발생초기등뼈가나타나기시작하면척삭은사라짐 (1) 미삭동물아문 (Subphylum Urochordata) - 피낭류와탈리아강류 1 피낭류 (tunicate) 유생 : 척삭, 등쪽의빈신경삭, 새열, 꼬리를갖는다. 성체로자라면서척삭동물의특징을잃는다 ( 꼬리, 척삭, 신경삭은몸속으로흡수되고새농 (gill sac) 만남는다 ) 여과섭식자, 순환계는개방형, 피낭이섬유소 (cellulose) 를포함 2 탈리아강류 (salp) 새열, 꼬리, 척삭을갖는어린개체의구조를성체에서도유지 ( 생식적인성숙만진행유형생식 ) 유형생식 (neoteny) (2) 두삭동물아문 (Subphylum Cephalochordata) - 창고기창고기 (lancelet) : 성체에서척삭이뚜렷, 성체두색동물 : 인두새열 (pharyngeal gill slit) 을유지하며, 등쪽에속이빈신경색발달, 몸은근육성이며, 반복되는근절로구성여과섭식자 ( 창고기 ) 로서성모를움직여물을빨아들이고, 입에있는촉수는먹이조각들을분리하는일을한다.

49 6) Chordates Chordates are defined as organisms that possess a structure called a notochord, at least during some part of their development. The notochord is a rod that extends most of the length of the body when it is fully developed. Lying dorsal to the gut but ventral to the central nervous system, it stiffens the body and acts as support during locomotion. Other characteristics shared by chordates include the following (from Hickman and Roberts, 1994): bilateral symmetry segmented body, including segmented muscles three germ layers and a well-developed coelom. single, dorsal, hollow nerve cord, usually with an enlarged anterior end (brain) tail projecting beyond (posterior to) the anus at some stage of development pharyngeal pouches present at some stage of development ventral heart, with dorsal and ventral blood vessels and a closed blood system complete digestive system bony or cartilaginous endoskeleton usually present.

50 A. Subphylum Urochordata - notochord, nerve cord, postanal tail only in free swimming larva, adults sessile, occasionally planktonic ; sea squirt (tunicates) B. Subphylum Cephalochordata - body laterally compressed and transparent (fish like), all four chordate characteristics persist throughout lifetime; Amphioxus C. Subphylum Vertebrata - notochord, nerve cord, postanal tail and gill slits at least present in embryonic stages, vertebrae surround nerve cord and serve as primary axial support, skeleton modified anteriorally into skull for protection of brain, features have enabled them to become predominate group of large animals. Classes : Agnatha lamprey, hagfish Chondrichthyes - sharks, skates, rays Osteichthyes- bony fish Amphibia Reptilia Aves- birds Mammalia

51 * 창고기 (amphioxus :Branchiostoma belcherii ) * 활유어 ( 蛞蝓魚 ; lancelet) 라고도한다. 몸길이 25~54mm 이다. 몸은버드나무잎모양으로가늘고길어어린물고기와비슷하다. 몸빛깔은연한복숭아색이고약간투명하다. 머리끝은뾰족하고그아래쪽에수염이달린주름이있는데, 그속에입이나있다. 물고기처럼등지느러미 뒷지느러미 꼬리지느러미가있다. 몸안에는탄력성이있는척삭이머리에서몸끝까지나있으며, 척삭둘레에는 64 개의근절 ( 筋節 ) 이있어이근육을움직여서운동한다. 혈관계는완전한폐쇄혈관계이다. 배쪽의굵은혈관일부가수축하여혈류를일으키고혈액은무색이다. 자웅이체이다.

52 * 척추동물의특징에의한분류 * 생물군 ( 특징 ) 원구류 ( 먹장어 ) 어류 ( 잉어 ) 양서류 ( 개구리 ) 파충류 ( 도마뱀 ) 조류 ( 참새 ) 포유류 ( 토끼 ) 신장의종류 전신 중 신 후 신 호흡기종류 아가미 아가미 / 폐 폐 양막의유무 없 음 있 음 체온 변 온 정 온 번식방법 난 생 태생 횡격막유무 없 음 있음 척추의유무 없음 있 음

53 (1) Fish (order: Pisces) Almost three-forths of the world's surface is covered in water. This water is home to over 20,000 different species of fish. The earliest fossils of fish date back over 400 million years. There are a wide variety of fish from the goby which is less than one half an inch long, to the whale shark which can be over 60 feet long. Most fish breathe through gills. Gills perform the gas exchange between the water and the fish's blood. They allow the fish to breathe oxygen in the water. Fishes are vertebrates that have a skeleton made of either bone or cartilage. About 95% of fishes have skeletons made of bone. These bony fishes have a swim bladder, a gas-filled sac, that they can inflate or deflate allowing them to float in the water even when not swimming. Fishes with a cartilage skeleton tend to be heavier than water and sink. They must swim to keep afloat. Cartilaginous (cartilage) fish include the ray and the shark. Most fish swim using a tail fin. Muscles in the tail fin move it from side to side, forcing water backward, and propelling the fish forward. Other fins help the fish change direction and stop. Pectoral fins on their side help them swim up and down. Dorsal and anal fins on the top and bottom keep the fish upright. Pelvic fins on the underside help steer left and right. Many fish eat plants, while others such as the shark, eat other fish.

54 2) 척추동물 (vertebrate) 발생시척삭 (notochord), 인두낭 (pharyngeal pouch) 이나인두열 (pharyngeal slit) 을갖는인두, 중추신경계 (central nervous system), 그리고척주 (vertebral column) 가척추동물의가장큰특징 1. 무악류 Agnatha a. 갑주어 Ostracodemis : 가장오래된화석상의척추동물 b. 원구류 Cyclostomes : 턱뼈와비늘이없으며, 가슴지느러미와배지느러미가없는척삭만있는원시적동물이다. - 칠성장어 (lampreys), 먹장어 (hagfishes) 2. 극어류 (Acanthodii) 와판피류 (Placodermi) : 화석상의가장오래된유악어류

55 (1) 무악어강 (Class Agnatha) - 턱이없는어류 a. 갑주어 (ostracoderm) : 갑주로무장되어있고턱이없다. 포식성아니고, 여과섭식자이다. 오르도비스기, 실루리아기, 데본기퇴적물에존재 b. 칠성장어 (lamprey) 와먹장어 (hagfish) : 원구아강 (Subclass Cyclostomata; 원형의입 ) 의구성원, 쌍으로된지느러미는없지만, 연골과척삭은일생동안유지 - 칠성장어 : 길거나빨아들이는구기를이용해먹이섭취경골의골격이없다. - 먹장어 : 부식동물 (2) 판피어강 (Class Placoderm ; 멸종한턱이있는어류 ) a. 갑주로무장했으며움직일수있고, 턱을갖음 ( 척추동물에있어가장중요한사건 ) b. 턱의발달 포식성먹이섭취의생태적지위확립 ( 턱은새궁에서유래 ), 경첩은턱의운동성향상시킴.

56 3. 연골어류 Chondrichthyes : 비늘과치아외에는경골이없고, 입이배쪽에위치. a. 판새류 Elasmobranchs : 편평한몸통과운동기관인앞지느러미, 5 쌍의새열 - 상어, 가오리, 홍어, 톱상어 b. 전두류 Holocephalans : 비늘이없고, 새열은덮개로덮여있다. - 은상어류 (chimaera) 4. 경골어류 Osteichthyes : 경골로된골격을갖고새열은아가미덮개로덮여있으며, 부레를갖고배설강이매우짧은것이특징. a. 조기어류 Ray-finned fishes : 기조와기막으로된지느러미를가지며, 내비공이없는경골어류이다. a-1. 연질어류 Chondrosteans : 내골격은연골로되어있고, 비늘에는경린 (ganoid scale) 이없다. - 철갑상어 (sturgeon), 용상어 (green sturgeon).

57 물고기머리닮은돌덩이... 알고보니 8 천만년전어류화석 영국켄트주에사는노부부가 15 년동안마당에장식해놓았던돌한점이무려 8 천만년전어류화석으로밝혀져화제가되었다. 텔레그라프, 데일리메일등주요언론에따르면피터 (74 세 ), 다프네파빈부부가이돌을발견한곳은휴가를보내기위해찾은서섹스주의페븐시근처해안이었다고. 평소특이한모양의돌을수집하기좋아하는파빈부부는물고기머리부분을닮은이특이한돌을놓치지않았고, 이들의집앞마당으로옮겨진돌은이후 15 년동안방문객들의눈길을한몸에받았다. 그러던중최근우연히만난켄트메이드스톤시의자연사박물관관련자가파빈씨에게전문감정을제안하였고결국이돌은 8 천만년전지구를헤엄쳐다니던진짜물고기의머리화석으로밝혀졌다. 메이드스톤자연사박물관장에드자젬보스키박사는이물고기가백악기에공룡들과함께공존했던견골어류의조상으로보인다며, 이들화석을개인적으로소장하고있는사람이있다는것은알았지만실제로확인하게되어놀랍다고전했다. 이런결과가나오자파빈씨는이화석을자연사박물관에기증하기로하였다.

58 The dumbest looking fish you will ever see!! This stupid looking fish inhabits the deep waters off the coasts of Australia and Tasmania. It is rarely seen by humans. The flesh of this goofy looking thing is primarily a gelatinous mass with a density slightly less than water.

59 Giant River Stingrays Found Near Thai City When anglers called that March afternoon to say they had caught a giant freshwater stingray near this bustling Thai city, biologist Zeb Hogan couldn't believe it. He had just spent a week in the remote Mekong River in northern Cambodia, searching for the ray which might be the world's largest freshwater fish species to no avail. Hogan, of the University of Nevada in Reno, is documenting the rays as part of the Megafishes Project, an effort to document Earth's 20 or so freshwater giants. Hogan is also a National Geographic Society Emerging Explorer. (National Geographic News is part of the National Geographic Society.) Many of these behemoths, including the giant stingray, have declined in recent years. The ray, listed as "vulnerable" on the 2007 World Conservation Union Red List of species, has been overfished in its Mekong River habitat, Hogan said. But when Hogan arrived at the river that afternoon, he found that not only had the anglers reeled in a 14-foot-long (4.3-meter-long) ray, but that the creature had also just given birth to a dinner plate-size baby. The newborn clung to the rough skin on the back of its mother, which was being held at the riverbank by nine handlers. (Stefan Lovgren in Chachoengsao, Thailand for National Geographic News, April 29, 2008)

60 나이 100 살, 230kg 철갑상어낚여 낚시꾼두명이무게 230kg 에 3m 가넘는길이의초대형철갑상어를낚아화제가되고있다고 17 일영국언론이보도했다. 언론보도에따르면, 영국콘월과에버딘에사는낚시꾼닉칼레야와조지카스테어스는최근캐나다브리티시콜럼비아프레이저강으로보트낚시여행을떠났다. 길이 3m 에약 230kg 무게의철갑상어는카스테어스의낚시바늘에걸렸는데, 물고기의힘이너무나강력해낚시도중보트에서떨어질뻔했다면서낚시꾼들은당시의아찔했던상황을회고했다. 낚시바늘에걸린초대형철갑상어가최소 100 살은넘은것으로보인다는것이이들낚시꾼들의설명이다. ( 중앙이보 ; )

61 A new scourge strikes Florida: Big, airborne fish On the water, there was reason to be anxious. Florida's season of "sturgeon strikes" - the law enforcement term for collisions between the state's largest freshwater fish and hapless boaters - was already well under way. It may seem bizarre, but it is no joke. Leaping sturgeon have injured three people on the Suwannee so far this year, including a woman on a Jet Ski and a girl whose leg was shattered when one of the big fish jumped aboard her boat. Eight others were hit last year, and with traffic growing on the storied river, sturgeon are joining alligators and hurricanes on the list of things to dread in Florida. "These injuries are very impressive," said Lawrence Lottenberg, director of trauma surgery at the University of Florida College of Medicine in nearby Gainesville. "You've got people sitting on the front of an open boat, and the boat is going 20, 30, 40 miles per hour. The fish jumps up and usually slaps these people right across their face and upper chest. Almost every one of them, universally, has been knocked unconscious. If you're not wearing a life jacket, you're going to fall in the water and potentially drown." Fortunately, most sturgeon in Florida stick to the Suwannee, which winds 265 miles, or 425 kilometers, from southern Georgia to the Gulf of Mexico. Known as Gulf sturgeon, they migrate between the river, where they spawn in spring and relax in summer, and the Gulf, where they return in the fall to feed. They have no teeth or temper, only a pressing, mysterious urge to jump all summer long.( articles/2007/07/04/news/fish.php)

62

63 (3) 연골어강 (Class Chondrichthyes) - 상어, 가오리등의포식자와부식성어류로구성. a. 보호용갑주와무거운골격을질긴피부, 가벼운뼈대, 빠른움직임으로대체 b. 연골성골격을원시적특성으로간주했으나, 최근상어의연골성골격이새로생겨난형질이라는데동의 상어척주에서결골조직의잔재발견 e.g. 연골성골격 : 심해의생활에적응하기위한진화 ( 부력용부레 (swim bladder) 가없다 ) * 상어 : 피부 - 질기며순린 (placoid scale ; 기부판에의해진피속에고정, 이빨과같은방법으로형성 ) 소화계 - 나선판 (spiral valve ; 칠성장어와일부경골여류 ) 은흡수성조직이창자안으로돌출되어있는것으로창자의표면적을넓힌다. spiral valve 는음식물을천천히이동하도록하여충분히소화되도록시간조절총배설강 (cbaca) : 배설계뿐아니라생식계에서오는관도연결, 출산관으로도작용모든척추동물에서발견되지만포유류에서대부분발생배에만존재감각기 - 측선기관 (lateral line organ) : 몸길이를따라있는관이며, 감각세포가있고, 물의움직임을감지, 체내수정을한다.

64 (4) 경골어강 (Class Osteichthyes) - 경골어류, 수생의거의모든생태적지위를차지한다. a. 경골어류의지느러미는상어에비해기동성이높다. b. 피부가비늘로덮여있고, 점액선으로표피를끈적끈적하게하여물과의마찰을 70% 까지줄임 c. 부레 : 평형을유지, 물속에서움직이지않고머무를수있게한다. - 가스샘 (gas gland) 으로부레에가스를분비, 재흡수부위 (reabsorptive area) 로가스제거 ( 가장진보된형태 ) d. 아가미필라멘트 (gill filament) : 가스교환장소 e. 순환계 : 2 개의심방을가지고근육질의심실은혈액을아가미로보내고, 아가미에서 CO2 와 O2 를교환 * 허파를가지고호흡하던민물조상에서부터진화해왔다고믿어지며, 3 개의그룹 1. 조기류 (Actincpterygii) - 지지성가시가있는납작하고얇은지느러미를가지며오늘날의경골어류가진화되어옴 2. 폐어류 (Dipneustei, lungfish) - 고도로맥관화된허파가인두에연결 3. 총기류 (Crossopterygii) - 육질의엽상구조에부착된납작한지느러미를가진다.

65 a-2. 전골어류 Holosteans : 경린에의해덮여있으나, 두부의비늘에는경린이없다 ( 동갈치 ; Lepisosteus spp.). a-3. 진골어류 Teleosts : 가장나중에진화된일반적인어류 ( 잉어, 농어, 뱀장어, 복어, 해마등 ) b. 육기어류 Lobe-finned fishes : 짝지느러미밑에육기 (fleshy lobe) 를가짐 b-1. 총기어류 Crossopterygians : 화석상의어류로호흡이가능한부레를가짐 b-2. 폐어류 Dipnoans : 비효율적인아가미를가짐. 부레로호흡을함 ( 폐어 ). 5. 양서류 Amphibia : 중신, 아가미나폐로호흡, 양막이없고난생, 변온동물 a. 미치류 Labyrinthodonts : 피부진피에골성비늘을가진화석상의양서류 b. 공추류 Lepospondyls : 도롱뇽형태의화석상의양서류

66 조기어류 (ray-finned fishes) 와육기어류 (lobe-finned fishes) Two types of bony fishes evolved from a common ancestor--the ray-finned fishes and the lobe-finned fishes (Unlike the smooth, ray-finned fishes, a lobe-finned fish has a fleshy scale covering the base of many fines ; 육기란내골격이있는근육부위와끝부분이지느러미로되어있는짝지느러미임 ). Coelacanth is the common name for an order of fish that includes the oldest living lineage of Sarcopterygii (lobe-finned fish + tetrapods) known to date.

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69 3 억 7 천만년전발달린물고기틱타알릭, 머리구조밝혀져 3 억 7 천 5 백만년전의틱타알릭은물고기에서육지동물로의진화과정을보여주는중요한화석동물이다 년처음으로틱타알릭에대한연구보고가나와큰화제를일으켰었다. 최대길이 2.7 미터이며악어와닮은틱타알릭은비늘과지느러미등물고기의특징과네발동물과닮은두개골, 목, 다리등을갖고있다는것이당시보고의내용이었다. 학술지 네이처 의 10 월 16 일자에는새로운연구결과가실렸다. 미국필라델피아자연과학아카데미의과학자들은틱타알릭의두개골내부를재구성해연구를진행한결과, 육지동물의머리와목의기원에가까운구조를갖고있다는사실이확인되었다고밝혔다. 틱타알릭의머리뼈가어깨뼈와분리되어있어목이자유로웠다고그덕분에얕은물에서머리를빼숨을들이쉬거나먹이를쫓을수있었을것이라는게연구팀의판단이다. ( 사진 : 시카고대학교의틱타알릭정보사이트자료 )

70 2006 년틱타알릭에대한첫연구논문이네이처지에발표됐을때당시연구를지원한내셔널지오그래픽소사이어티 (NGS) 와미국과학재단 (NSF) 은 " 지구생물체의진화를이해하는결정적인단서를찾았다 " 고환호했다. 뉴욕타임스 (NYT) 지는 " 창조론에맞서는강력한방증이될것 " 이라고평했다. 틱타알릭이처음세상의주목을받은것은지느러미가다리로진화해가는과정을보여준데있다. 지느러미뼈에는사람으로치면팔목과팔꿈치구조가있었다. 과학자들은틱타알릭이얕은물속에살면서잠시육지에올라와지느러미로땅을짚고움직였을것으로추정하고있다. ' 틱타알릭 ' 이란이름도에스키모말로 ' 얕은물에사는큰물고기 ' 라는뜻이다.

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73 (2) Amphibians (class: Amphibia) Amphibians lay their eggs in water, and young amphibians tend to resemble small fish. The tadpole, or newborn frog, is born and lives in water. It has a tail that allows it to swim like a fish. It also has gills so that it can breathe under water. As the tadpole grows into a frog, it loses its gills and tail, and develops legs for moving on land. Most amphibians can both walk and swim in water. Depending on the species of amphibian, breathing can take place in gills, lungs, the lining of the mouth, the skin, or some combination of these. Amphibians body temperature changes with its environment. In cold climates, amphibians hibernate during the winter.

74 (3) Reptiles (class: Reptilia); lizards, snakes, and others Reptiles have been around for 300 million years, even during the dinosaur age. The most common reptiles include alligators, crocodiles, lizards, snakes, tortoises and turtles. Reptiles are air-breathing animals, although many live not only on land but in water. The most noticeable feature of reptiles are the scales that cover their body. The majority of reptiles lay eggs to give birth to their young. Reptiles are often called cold-blooded because they can't regulate their own body temperature. Their body temperature depends on the external temperature. They will lay in the sun to heat their body, or hide in the ground, under a rock or in water to cool their body. Crocodiles and alligators are large reptiles that spend much of their time on land and in water. They can walk on land using their webbed feet. They can also use their long tail to swim in water. Crocodiles feed on large animals they catch on land or in water. They have powerful jaws and teeth to tear apart their prey. Lizards and snakes are the largest group of reptiles. Lizards are four legged animals with a long tail. Many lizards can shed their tail to escape from predators. They can then grow a new tail. Some lizards, such as the chameleon, can change colors to blend into their environment. This camouflage helps to protect them from predators. Snakes don't have limbs. They move by slithering along the ground. Some snakes are poisonous, or venomous, such as the rattle snake, cobra, and eastern green mamba. They have fangs which bite into their prey and inject poison into the victim. Other snakes, such as the boa constrictor and the python kill their prey by crushing it. Most snakes can dislocate their jaw, allowing them to swallow prey much larger than themselves.

75 c. 진양서류 Lissamphibians : 현존하는일반양서류 c-1. 유미류 Urodeles : 유생단계에아가미로호흡하며꼬리를갖는양서류 ( 도롱뇽등 ) c-2. 무미류 Anurans : 꼬리가없는양서류 ( 개구리, 두꺼비등 ) c-3. 무지류 Apodans : 다리가없는양서류 (caecilian) 6. 파충류 Reptilia : 후신, 허파호흡, 양막이있고, 난생의변온동물 a. 무와류 Anapsids : 늑골과척추가유착된골성피부판껍질을가짐 ( 거북 ) b. 유인류 Lepidosaurs : 뱀, 도마뱀등 c. 공룡류 Archosaurs : 중생대의번성하였던화석상의육상척추동물 ( 공룡 ) 과악어류 d. 기룡류 Euryapsids : 멸종한해산파충류 e. 단와류 Synapsids : 포유류의조상으로생각되어지는화석상의파충류

76 (4) 양서강 (Class Amphibia) - 양서류 a. 양서류와파충류는원시육상그룹이었던미치류 (labryrinthodont) 로부터진화되었다고추측 - 석탄기암석에서발견 b. 엽상지느러미어류의골격과화석양서류의골격에차이점이있다. c. 3 개의방으로된심장 - 혈액순환로를통해허파와연결되어있고허파가몸의나머지부분과분리되어있다는점에서어류보다진보, 그러나불완전하여산소가풍부한피와산수가없는피가하나의심실에서섞이게된다. d. 축축한피부 : 허파와함게양서류의중요한호흡기관 e. 수서생활 : 가스교환하는피부로물도통과할수있기때문에탈수의위험이있다. f. 대부분물속에서체외수정 g. 무족영원류와대부분의도롱뇽은체내수정 양서류는반수서동물이며, 진정한육상생활을하게된최초의척추동물은파충류이다.

77 피터팬양서류 악솔로틀, 도룡뇽으로변신해화제 변태과정을거치지않고유생모습그대로성장하는것으로알려진희귀양서류 악솔로틀 한마리가도룡뇽으로변신하고있다고지난주노스데본가제트등영국언론이보도했다. 언론에소개된이후독특한외모때문에 피터팬양서류 로불리며해외네티즌들의눈길을사로잡고있는주인공은영국데번주사우스몰턴에서자라고있는애완용악솔로틀 ( 도룡뇽의일종 ; axolotl) 딜리. 딜리는태어난지약한살이지났는데, 외부에돌출된아가미가점점사라지고있는등변태과정을겪고있는것으로보인다는것. 딜리의이같은변화에대해동물전문가들은놀랍다는반응을보이고있는데, 자연상태에서아가미호흡을하며평생을보내는것으로알려진악솔로틀이도룡뇽으로변태하는것을처음목격했다는것이한동물전문가의설명. 악솔로틀은멕시코원산으로멕시코도룡뇽으로도불린다. 다른도룡뇽과는달리외부에돌출된 6 개의겉아가미가평생사라지지않는것이특징인데, 웃음을짓는것같은표정과성장을하지않는특성때문에 피터팬 으로불리기도한다. 짙은분홍색의겉아가미가점점사라지며도룡뇽으로변신하고있는딜리가조만간허파호흡을할것으로전망된다고언론은덧붙였다. ( 사진 : 도룡뇽으로변신중인피터팬양서류 딜리 의모습 / 영국언론보도화면 )( 조선일보 ; )

78 * 국내에서식하는양서류 (18 종 ) *

79 식욕왕성 ~ 볼링공크기.. 공룡새끼잡아먹던 지옥개구리 ' 발굴 6500 만 ~7,000 만년전새끼공룡을잡아먹고살았던것으로추정되는 ' 개구리 ' 의화석이발굴되었다고 19 일해외언론들이일제히보도했다. 미국뉴욕스토니브룩대학교연구팀이공개한이고대개구리는강력한이빨, 갑옷처럼단단한피부로무장했으며다리부위를제외한몸통길이는 40cm, 무게는 4.5 kg 에달한다. 무시무시한외모로인해 ' 악마개구리 ', ' 지옥에서온두꺼비 ' 라는이름이붙여진이고대동물의화석은마다가스카르에서발견되었다. 라틴어로악마와두꺼비를뜻하는 ' 벨제부포 ' 라는이름이붙여진이개구리는현재지구상에살아가는가장큰개구리인말라가시개구리보다훨씬몸집이큰것이특징이며, 도마뱀및심지어갓부화한새끼공룡등을잡아먹었을것이라고연구팀은밝혔다. 공룡을잡아먹고살았던 ' 악마개구리 ' 가현대남아메리카에서식하는 ' 뿔개구리 ' 와친척관계에있는것으로보인다는것이연구팀의설명. 갑옷과같은피부, 커다란입, 날카로운이빨을가진개구리의상상도는언론을통해보도된후인터넷사이트등을통해알려지면서네티즌들사이에서도큰화제를낳고있는중. 악마개구리, 지옥에서온두꺼비에대한상세한연구결과는미국국립아카데미과학저널을통해공개되었다. ( 사진 : 새끼공룡을잡아먹고살았던것으로추정되는 ' 악마개구리상상도 ' / 연구팀보도자료사진 )

80 호주서몸무게 1 kg ` 괴물두꺼비 ` 포획 몸길이 45 cm에체중은거의 1 kg이나되는강아지크기의두꺼비가 26 일호주북부도시다윈에서발견됐다. 자원봉사단체인프로그워치가발견한이거대한두꺼비는보통두꺼비의거의두배크기로지금까지호주에서발견된두꺼비가운데가장크다고이단체의그라엠소여국장은밝혔다. 그는 " 이처럼큰두꺼비는보통암놈인데이번에잡힌것은수놈 " 이라면서 " 이수놈의짝을볼까겁난다 " 고말했다. 피부에독이있는두꺼비는호주생태계를파괴하는주범으로인식돼왔으며프로그워치는 ' 두꺼비정복자 '(toadbuster) 프로젝트하에정기적으로두꺼비포획에나서고있다. 호주는 1935 년북부사탕수수농장에서식하는딱정벌레를없애기위해하와이에서두꺼비를들여왔으나이두꺼비를잡아먹은뱀과악어수백만마리가죽는등생태계교란을일으켜이두꺼비는호주의정책실패가가져온환경재앙으로여겨지고있다. 호주당국은이두꺼비를잡아냉동시킨뒤액화비료를만드는등퇴치에혼신을다하고있으나현재이사탕수수두꺼비개체수는거의 2 억마리에이르는것으로알려졌다. ( 시드니다윈 AP ㆍ로이터 = 연합뉴스 )

81 (5) 파충강 (Class Reptilia) - 파충류 < 비늘로덮여있다 > a. 건조한환경에대한적응 : 효율적교미와체내수정을위해음경 (penis) 발달 b. 양막이있는알로진화 ( 양막속의액체 - 배보호 ) c. 발생배, 조류, 육상곤충과같이요산 (uric acid) 을만들어제거함으로써수분손실을피함 e. 건조한피부 - 수분손실극소화 ( 신축성이없어탈피를해야함 ) f. 허파 : 수많은구획으로나뉘어있고스펀지조직을가진다. g. 심장 : 3 개의방으로구성되며, 부분적격벽에의해심실이나뉘어있다 ( 크로토다일이나엘리케이터의심실은격벽이완전하여 4 개의방형성 ) h. 외온성동물 (ectotherm) : 외부온도가변할때마다체온도변함 i. 파충류의물질대사는느림 적은음식으로도생존가능 j. 시각, 온도감각, 후각, 청각등의수단으로먹이포획또는독물사용.

82 (=terrapin)

83 Rescuers work to net Vietnam s sacred turtle Thousands of Vietnamese jostled and climbed trees around a lake in the capital on Tuesday hoping to see a rare giant turtle considered sacred by many but in desperate need of medical attention. Dozens of workers waded chest-deep through the chilly green water in Hanoi s Hoan Kiem Lake to try to capture the giant freshwater creature for the first time, so it could be pulled to an island and treated. It is one of the world s most endangered turtles one of only four Rafetus swinhoei believed to be alive today but its value to the nation transcends the natural world. The turtle traces its roots back through hundreds of years of local folklore, and some even believe the animal that lives in the lake today is the same mythical creature said to have helped a Vietnamese king fend off the Chinese nearly six centuries ago. In recent days, photos of it surfacing with open pink sores on its wrinkled neck and legs have sparked near panic among the public, with newspapers carrying frontpage stories and online chat rooms buzzing. Lesions were also visible on its shell, which stretches 1.8 meters long and 1.2 meters wide. Some experts fear the water in the sewage-filled and trash-strewn lake is slowly killing the turtle, which is thought to weigh about 200 kilograms and is affectionately called great-grandfather. Hundreds of Vietnamese have been working around the clock removing chunks of debris from the lake and pumping in fresh water.

84

85 * 악어의사육과분류 * 악어는내비공 치열 비늘판등의구조에따라크게앨리게이터과 크로코다일과의 2 과로나뉜다. 악어는주로동남아에서고기와가죽을이용하기위하여야생상태의어린악어를잡아기르는형태 (ranching) 에서, 최근에는집약적인양식 (intensive farming) 형태로사육되고있다. 전염성의질병은잘알려져있지않으나, 악어는변온동물이므로사육적정온도 (28-33 ) 를유지해야하며, 이를위해숨을수있는사육시설과위생적인사육관리가요구된다. 1. 앨리게이터앨리게이터 (alligator) 과는다시 4 속 7 종으로나뉘는데, 입을다물때아래턱니가위턱니의안쪽으로들어가며위턱의네번째이빨이가장크다. 현재앨리게이터는북아메리카와중국에 1 종씩떨어져분포하고있는데, 화석종으로미루어보아연속적으로널리분포했던것으로보인다. 가장큰것은미시시피악어 (Alligator mississippiensis) 로몸길이 3 6m 이다. 양쯔강악어 (A. sinensis) 는몸집이작고양쯔강주변에서식한다. 특히카이만 (caiman) 아과에안경카이만 (Caiman crocodilus), 넓은입카이만 (C. latirostris), 검정카이만 (Melanosuchus niger) 등이있다. 주로중남미에분포, 서식한다. 2. 크로코다일크로코다일 (crocodile) 과에는 5 속 16 종이포함되며주둥이가엘리게이터에비해더욱가늘고삼각져있다. 위 아래턱의이빨이같은수직면에있기때문에입을다물면서로맛물리는데위턱의다섯번째이빨이가장크다. 가장큰것은몸길이 7 10m 에이르는인도악어 (Crocodylus porosus) 이고성질이난폭한종이많다. 나일악어 (C. niloticus), 아메리카악어 (C. acutus) 등이이과에속한다. 주로아프리카와아시아, 그리고북미에분포, 서식한다. 특히가비알 (gavial=gharial) 아과는위턱뼈와비골이닿아있지않은점에서독립된과로분류하였으나현재는크로코다일과에포함시키고있으며, 인도가비알 (Gavialis gangeticus), 말레이가비알 (Tomistoma schlegeli) 등이있다. 그림. 좌로부터 ; 앨리게이터, 카이만, 크로코다일, 가비알

86 서울대공원코모도왕도마뱀수입 지구상에서가장큰도마뱀인 ` 코모도왕도마뱀 (Komodo dragon)' 한쌍이서울대공원에온다. 서울대공원관리사업소는이르면 6 월인도네시아로부터코모도왕도마뱀을암수한마리씩수입할계획이라고 16 일밝혔다. 인도네시아코모도섬과그주변에만살며, 멸종위기야생동물로국제적인보호를받는인도네시아의 ` 국보 ( 國寶 )' 급동물인코모도왕도마뱀은몸길이최대 5m, 몸무게 150 kg까지자라고사슴과멧돼지등큰짐승들을먹잇감으로삼고, 사람도공격하는것으로알려져있다. 대공원은최근능구렁이등토종파충류를한쪽으로몰아내고방세칸에자동온도센서와자동개폐식유리창까지달린숙소를마련했다코모도도마뱀은현지인들에게는 ' 오라 (ora)' 라고불리는데, 세계에현존하는약 3,400 종의도마뱀중에서가장크며굉장히사납다. ( 연합뉴스 ; )

87 15m 길이 ' 바다괴물 ' 북극서화석발견돼 1 억 5000 만년전쥐라기에생존했던거대한 ' 바다괴물 ( 왼쪽맨아래 )' 의화석 ( 오른쪽아래작은사진 ) 이최근노르웨이북극권에서발견됐다. 몸길이약 15m 로추정되는이 ' 바다괴물 ' 은그림에서처럼범고래 (killer whale, 맨위 ) 와흰긴수염고래 (blue whale, 가운데 ) 의중간크기이며, 지금까지발견된해양파충류중덩치가가장크다. 그림속에서 ' 바다괴물 ' 이삼키려하는물체는인간잠수부. ' 바다괴물 ' 은정식학명 ( 學名 ) 이아닌별칭이다.

88 (4) Birds (class: Aves) There are over 8,000 species of birds. Birds have 3 major differentiating characteristics: wings for flight, feathers, and a beak rather than teeth. Birds have adapted their vertebrate skeleton for flight. Their bones and skull are very thin, making their bodies extremely light. To support flight also required other changes to their skeleton. Obvious changes are the addition of wings. Other changes are less obvious. The claws and muscles of a bird's foot are designed to lock and hold onto a perch even while the bird is sleeping. A bird's respiratory system is also adapted to make it easier to breathe at high elevations, where air is thinner. Aquatic animals include for example the seabirds, such as gulls (family Laridae), pelicans (family Pelecanidae), and albatrosses (family Diomedeidae), and most of the Anseriformes (ducks, swans and geese).

89 7. 조류 Aves : 정온동물로난생. a. 고조류 Archaeornithes : 화석상의조류 ( 시조새 ) b. 신조류 Neornithes : 현존하는일반조류 ( 갈매기, 펭귄, 황새등 ) 시조새 (archeopteryx) 8. 포유류 Mammalia : 태생의횡격막이있는정온동물 a. 단공류 Monotremata : 총배설강을갖는난태생의동물 ( 오리너구리, 가시두더지 ) b. 유대류 Marsupialia : 육아낭을갖는원시적포유류 ( 캥거루, wallaby, 주머니쥐 ) c. 식충류 Insectivora : 주로벌레를먹는하등포유류 ( 고슴도치, 두더지 ) d. 익수류 Chiroptera : 날수있는척추동물 ( 박쥐 )

90 (5) Mammals (class: Mammalia) Mammals have several unique characteristics that differentiate them from other animals. Most mammals have hair, or fur, covering their body. They are also capable of regulating their body temperature. The mammal s metabolism controls heat production, and the sweat glands help cool the body. These allow the mammal to maintain a constant body temperature, regardless of the environmental temperature. One other difference is that mammals give birth to fully formed babies, and the female mammals produce milk to feed their young. Most mammals walk on 4 legs, with only the humans walking upright on 2 legs. Aquatic mammals have flippers, or fins, for swimming rather than legs. Common mammals include: primates, such humans and monkeys; marsupials; rodents; whales; dolphins; and, seals.

91 e. 영장류 Primates : 손가락이발달 ( 원숭이, 인간 ) f. 식육류 Carnivora : 육식을하는동물 ( 고양이, 곰, 바다사자, 물개, 바다표범 ) g. 고래류 Cetacea : 영원한수서포유류 ( 고래, 돌고래 ) h. 빈치류 Edentata : 치아가없는동물 ( 나무늘보, 개미햝기 ) i. 설치류 Rodentia : 상하한쌍의문치를가짐 ( 쥐, 다람쥐 ) j. 토형류 Lagomorpha : 상하두쌍의문치를가짐 ( 토끼 ) k. 유제류 Ungulates : 발가락끝 ( 발굽 ) 으로걸음. 초식동물 ( 소, 코뿔소, 코끼리 ) l. 해우류 Sirenia : 원시유대류의변이된후손 (manatee)

92 * 오도가도못해 ~ 얼음덩어리위난감한북극곰, 사진화제 * 얼음덩어리위에서북극곰이난처한포즈로앉아있다. 이사진은 23 일결과가발표된 2007 년쉘야생생물사진가 콘테스트에서수상한작품이다. 콘테스트는영국자연사박물관이주관하며에너지기업쉘이후원하는유명사진경연이벤트. 노르웨이와러시아사이의바렌츠해에서촬영된사진을보면, 북극곰은작은얼음덩어리위에어정쩡하게앉아있다. 이작품은 하나의지구 부문에서 2 위를차지했다. 최근과학자들은기후변화로북극해의빙붕이녹아북극곰들이먹이를잡기위해최대 100km 까지수영하는일이벌어지고있으며이때문에북극곰의익사사례도늘고있다고주장했다. ( 팝뉴스 /PopNews)

93 (7) 포유강 (Class Mammalia) - 포유류 1 포유류의뇌 : 유전적본응에덜의존하고, 각자의경험과학습에의한행동에의존 환경에더욱쉽게적응 2 포유류의기원 : 피름기에파충류인수궁류로부터진화젖 : 성장단계동안고단백질과고칼로리제공 어린개체는젖을얻기위해최소한한쪽부모와남게되었고, 어버이로부터배울수있는기회를주었으며, 뇌에대한자연선택을강요하는원인이됨 * 중생대말기에 3 개의그룹형성 1. 단공류 (monotreme; 알낳는포유류 ) : 오리너구리, 가시두더지두종류만현존 2. 유대류 (marsupialiorder Marsupalia; 주머니포유류 ) : 난황주머니의변형인의태반 (pseudoplacenta) 을만들어내고의태반이짧은기간동안배발생을돕는다. 3. 태반류 (placental mammal; 태반을형성하는포유류 ) : 태반이자궁에서발생되는배에영양분제공 3 영장류 (Primates) 호미니드 (hominid) : 사람과에속하는모든구성원 ( 긴팔원숭이, 오랑우탕, 침팬지, 고릴라, 사람 ) 을일컫는말초기영장류 : 긴코와발톱을가졌으며, 설치류와비슷했고거의비슷한생태적지위점령수족과몸은대부분나무에살도록적응, 눈이잘발달되어있고입체시각뇌는학습에맞도록적응, 잡식성으로변화되면서이가상대적으로특수화되지못함 4 인간의특수화엄지손가락의특수한근육조직배열로정교한기구제작가능아치형으로발달된발과엉덩이근육에의해직립보행가능, 커다란뇌와언어능력발달

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