Động vật có xương sống biển pot

Tổng lớp không hàm Agnatha• Đặc điểm chung – Thuôn dài, dạng lươn, da trần và có nhiều tuyến nhầy – Bộ xương ở dạng màng, chủ yếu là mô liên kết và sụn – Xương trục mới chỉ có dây sống,

Động vật biển có xương sống

(Marine Vertebrates)

Ngành dây sống ( Chordata )

– Phân ngành: sống đuôi ( Urochordata )

– Phân ngành: sống đầu ( Cephalochordata )

– Phân ngành: động vật có xương sống ( Vertebrata )

phân ngành của Chordata, thuộc lớp

( Vertebrata) Là những sinh vật có cấu

trúc phức tạp nhất

Các lớp sinh vật biển cơ bản của

Có 7 lớp chính trong ngành ĐVCXS là:

1 Tổng lớp không hàm (Agnatha)

- Lớp Giáp vây (Pteraspidomorphi)

- Lớp Giáp đầu (Cephalaspidomorphi)

Tổng lớp không hàm (Agnatha)

• Đặc điểm chung

– Thuôn dài, dạng lươn, da trần và có nhiều tuyến nhầy

– Bộ xương ở dạng màng, chủ yếu là mô liên kết và sụn

– Xương trục mới chỉ có dây sống, chưa có cột sống,

– Hộp sọ chưa phát triển, chưa phân hóa thành cung hàm

– Cơ quan hô hấp dạng túi

– Giác quan kém phát triển: chỉ có một lổ mũi thông với ống mũi hầu; mắt, tai cấu tạo không đầy đủ

• Tổng lớp không hàm có 75 loài, đại diện là cá bám đá (Lamprey) và hagfish

Phân loại tổng lớp không hàm

– Phân lớp Giáp khác (Heterostrasi)

– Phân lớp Vẩy rỗng (Coelolepida)

– Phân lớp Giáp xương (Osteotraci)

– Phân lớp Giáp thiếu (Anaspida)

Cá Bám đá

(Lamprey)

• Miệng tròn Có giác bám Sống ký sinh và bán ký sinh

• Có 2 vây lưng Ống mũi hầu bít đáy Ống hô hấp tách khỏi ống tiêu hóa

7 đôi túi mang lỗ riêng thông với môi trường ngoài.

• Mắt hiện rõ dưới da và cò thủy tinh thể, nhưng thiếu võng mạc, củng mạc, tai trong mới có 2 ống bán khuyên.

• Đơn tính Trứng ít noãn hoàng, nên cá thể phải qua giai đoạn ấu trùng,

• Tất cả 3 lớp đầu tiên trong ĐVCXS đều có dạng cá

• Tổng lớp không hàm (Agnatha) có 75 loài, đại diện là hagfish và Lampreys

• Lớp cá sụn (Chondrichthyes) có 800 loài, đại diện là cá đuối (rays) và cá mập (sharks)

• Lớp cá xương (Osteichthyes) gồm tất cả các loại cá có xương sống

• Lớp Bò sát (reptiles),

• Lớp Aves (chim) và

• Lớp Thú (Mammalia) thì cũng phổ biến cả trong môi trường đất và biển

• Có khoảng 27.000 loài cá, 2.200 loài lưỡng cư, 6.000 loài bò sát và 4.400 loài động vật có vú trong lớp ĐVCXS.

• Hagfish thuộc bộ Myxiniform They

are related to the slimefish They

have the peculiar habit of tying

themselves into knots in order to

shed their slime coat and make a

new one.

Phễu miệng của cá Bám đá

Tấm lưỡi

Rèm da Răng bên

Tấm hàm dưới Tấm hàm trên

Phân bố của cá Bám đá

Cấu tạo trong của ấu trùng Ammocoetes

Mặt cắt qua hầu của cá Bám đá

Lớp Myxin (Myxini)

Lớp cá sụn (Chondrichthyes)

• Các cá này thì không có xương cứng, cấu trúc bộ xương của chúng là xương sụn (cartilage).

• Lớp này là một trong những loài cá biển đầu tiên để phát triển thành cá có các cặp vây.

• Chúng có 5-7 lược mang.

• Thiếu bóng hơi (swim bladder) Do thiếu bóng hơi đã tạo ra nhu cầu cho cá mập là phải bơi liên tục để tránh bị chìm Việc bơi liên tục cũng giúp cho việc duy trì dòng nước và oxy qua mang và qua miệng của chúng.

• Da của chúng được bao phủ trong các vẩy răng (denticles) nên làm cho nó có vẽ ram ráp (nhám).

• Sinh sản bằng phương pháp thụ tinh trong.

• Các loài này có lá gan lớn để mà có thể chứa nhiều dầu phục vụ cho việc nổi.

Bộ đuối cưa (Pristiformes)

Bộ đuối lưỡi cày (Rhinobatiformes)

Bộ đuối quạt (Rajiiformes)

Bộ đuối ó (Myliobatiformes)

Bộ đuối điện (Torpediniformes) Phân lớp toàn đầu (Holocephali

Bộ cá Khime (Chimaeriformes)

Cá mập

• Sharks do not have swim bladders, and if they were to stop moving they would probably sink to the bottom of the ocean; therefore, they are usually constantly in motion

• Sharks usually are scavengers, eating injured fishes, carrion, garbage, and other waste from ships as well as animals such as seals, turtles, birds,

whales, crabs, and a wide range of fishes

• The whale shark is the largest shark and also the largest fish in the sea, measuring up to 15 m (49 ft) in length; the cookie-cutter shark measures less than 50 cm (19 in) in length Usually there are five gill slits that lie

behind the head The tail's symmetry is termed cercal because of its

irregular shape (1)

Cá Mập trắng khổng lồ

Cá Mập trắng khổng lồ

Cá mập lưỡi búa

Whale shark

and is a technique many marine animals use for protection as well

as for predation Countershading makes the animal almost invisible because when another animal looks down at them, they are

camouflaged with the darkness of the sea bottom When looked up

at from underneath, the animal is camouflaged with the light from the sun Great White Sharks use this technique for predation

Skates and rays swim using rajiform swimming.

trường nước biển và nước ngọt Chúng có nhiều đặc

điểm sinh sản và thích nghi khác nhau.

– Cá ngựa: cá đực mang trứng và nuôi con.

– Cá biển sâu: sống ở tầng nước rất sâu, nơi có ánh sáng yết Do

đó chúng tạo ra ánh sáng cho riêng nó như ngọn đèn trên đỉnh đầu của nó.

Lớp cá xương ( Osteichthyes )

nước ngọt.

Chữ Fishes thường bao hàm cả trong hình dáng, kích cở của loài cá sống trong vùng biển Chúng có kích cở từ rất lớn đến 3m (cá ngừ vây xanh) đến các loài

bé tí nị dài chỉ khoảng 7mm.

nhiệt độ cơ thể của chúng, nhưng không có ở loài động vật có vú.

cơ tốt hơn, các tín hiệu thần kinh tốt hơn và hệ thống tiếu hóa khá phát triển.

Phân loại cá xương

1 Phân lớp cá vây tia (Actinopterygii)

Bộ một phổi (Monopneumones)

Bộ hai phổi (Dipneumones)

The following are some more pictures of other fish:

Angel fish

Cá nóc gai

Cá ngừ

Cod

Diagram of the skeleton of a boney fish

Diagram of the skeleton of a boney fish

Răng

Cung mang, Sợi mang, Lược mang, Nắp mang

Các vị trí đo đạc

Cơ quan hô hấp phụ

Detail of the bones of lungfish (water to air

transitions)

Diagram of the circulatory system and heart

of a bony fish

Description: "Brain of Perch Lower aspect

Lớp bò sát ( Reptilia )

• Reptiles are vertebrates in the class Reptilia, which includes four orders: Testudines (turtles, terrapins, and tortoises), Squamata (lizards, worm lizards, and snakes), Crocodilia (crocodiles, alligators, gavials, and caimans), and Rhynchocephalia (two types of tuatara) The majority of marine reptiles are sea turtles, although there are a few marine snakes and marine iguanas Sea turtles, crocodiles, and alligators are all classified under marine terapods, a classification containing all reptiles with four legs In general a reptile is an animal that has very strong, dry skin sometimes covered with scales Reptiles are cold-blooded or ectothermic, use lungs to breathe, and have tough skin without feathers or hair Although reptiles are most commonly found in tropical environments and deserts, they are also found

in lakes, ponds, oceans, and even on top of mountains Because they cannot regulate their internal body temperature , they are not found in extremely cold climates

• The more than 250 species of turtles and tortoises all have a protective shell surrounding their body They range in size from the huge leatherback sea turtle, which can reach up to 8 ft long and weigh over 2,000 lbs to the smallest bog turtle that measures only 4.3 in at most Turtles that live in water have a lighter, flatter shell than the terrestrial species

• Lizards are the most common reptile with more than 4,300 species Lizards usually have four legs with clawed, however there are exceptions such as the worm lizard that sometimes has no appendages at all Lizards range from 1.5 inches to 10 feet long, are typically insectivores, and inhabit trees, shrubs, or rocks Some lizards will eat other vertebrates and others only eat plants The Galapagos Islands are home to marine iguanas, the only lizards that venture into the ocean

• Snakes are basically reptiles with no appendages There are about 2,500 species of snakes in the world measuring between 5 in to 33 feet in length Snakes are thought to have evolved from lizards Unlike other reptiles, snakes lack outside ears and have eyes covered with permanent transparent scales Snakes have adapted to almost all habitats in the world and can also be found on lakeshores and even in ocean waters Sea snakes have a specially adapted flat tail that makes it easier for them to swim

Lớp bò sát ( Reptilia )

13 feet long but some, like the saltwater crocodile, can reach up to 33 feet Crocodilians are usually found in tropical waters, although some alligators live in temperate climates especially in the US and China Crocodilians have long flattened tails that enable them to swim efficiently through water They breathe through nostrils located

at the top of their head.

Reptiles also have a three chambered heart with the exception of crocodiles, which have four chambers like

mammals or birds The digestive system of reptiles differs from other vertebrates in that waste, including that from the urinary system, the sexual organs, and the digestive system, empties into a holding tank called the cloaca In the cloaca, water can be reabsorbed into the body to be used again.

skin as a form of protection from other animals and for protection during mating rituals Some reptiles have the ability to change color for camouflage, communication, or sexual attraction They reproduce through internal fertilization Male lizards and snakes often have two penises; most male turtles and crocodiles have one The two penises are referred to as hemepenes and the animals only use one of them while mating Species that mate with more than one female at a time usually alternate the hemepenes Most reptiles lay eggs, although some lizards and snakes actually give birth to live young Reptile eggs contain yolk and protein and are protected by a leathery

or hard shell, which allows carbon dioxide and water to be exchanged while protecting the embryo from drying out or consumed by bacteria Some small turtles, like the African tortoise, only lay 1-2 eggs at a time Sea turtles have been known to lay 150 eggs multiple times every season Sea turtles lay their eggs in the sand and then leave them to hatch alone The large number of eggs is necessary because many hatchlings do not survive They are vulnerable to predation by birds, snakes, mammals, and sharks and to coastal development Sea turtles that

do reach maturity can live up to 120 years in the wild Alligators also have a long life span up to 70 years.

Marine Reptiles

• The majority of marine reptiles are sea turtles; however, there are some sea snakes and some marine lizards (like those found on the

Galapagos Island) Sea turtles fall under the

catergory of marine terapods which are marine organisms with four legs Crocodiles and

alligators also fall under this catergory Most

marine turtles are endangered or threatened

and so it is important to take measures to keep their numbers from declining further.

Loggerhead turtle (Caretta caretta)

Sea turtle

Rùa đang ăn plastic tưởng là thực phẩm

Lớp Chim (Birds)

• Marine birds are characterized by a variety of adaptations to marine conditions These adaptations include the ability of feathers to resist water, salt glands, curved bills, and webbed feet Many marine birds are able to dive into the water to capture prey and some birds, like penguins, are able to swim into deeper water

• The preening gland releases waxes and water repellant fats that create a protective shield on the bird to prevent water from saturating the feathers This protective shield also keeps the bird insulated and, when combined with feathers made out of dusty keratin, the bird is waterproof Salt glands allow marine birds to drink salt water and expel the unusable salt from their bodies Salt glands work by

condensing salt from the blood into the sinuses allowing the bird to sneeze out the excess Other marine birds push out salt directly from the glands The freshwater needed for survival comes from their prey

• The curved bill found in penguins and cormorants is an adaptation that helps birds bring fish into their throat Many marine birds dig into the sand for prey Some have a distensible pouch such as those found in pelicans, frigate birds, and cormorants This pouch is located between the two parts of the lower mandible and is used to drain water from around the fish before it is eaten Cormorants and

Anhingas use the hooked bills to puncture their fish Frigate birds snatch fish from other birds Flamingos have a beak that can filter small invertebrates, algae, and other small organisms from water These birds have long bills and long legs, enabling them to stand in shallow water while searching for food

• Many birds will fly directly above the surface and look for fish swimming below Black skimmers fly close to the surface and pluck fish at the top out of the water Gulls and terns like to fly higher to view the fish and plummet from the air to snatch the fish out of the water The penguin is an unusual but very familiar marine bird that can dive down into the ocean to look for fish

• As well as having a multitude of hunting strategies and bill adaptations, marine birds also have many different types of legs and feet If a bird has very short legs with webbed feet, it is probably a very powerful swimmer Webbed feet are referred to as totipalmate feet and partially webbed feet are referred to as palmate feet Birds that do a lot of swimming often rely upon what is called countercurrent exchange to keep the cold blood flowing up and away from their feet from shocking their body The arteries in these birds run very close

to veins on the way up and are warmed enough that the bird can swim in very cold water without negative effects Many marine birds also have very well developed eyesight and an amazing sense of smell Birds like the tube nosed bird, petrels, and the albatross can smell food 30 km away

• Marine birds are important to the ecosystem for many reasons including their ability to move seeds throughout the environment, their predatory role in the ecosystem, and their ability to inspire and interest humans However, they are threatened greatly by loss of habitat, oil spills, entanglement in fishing nets or garbage, and disruption in migration due to global warming

Lớp Động vật có vú (Mammals)

• Marine mammals are vertebrates that have hair or fur, are warm blooded, use lungs to breathe air, bear live young, and produce milk through mammary glands Marine mammals are very similar to land mammals with the exception of the thick layer of blubber instead of thick fur for insulation They typically have long bodies, which allow them to move swiftly through the water Although they breathe air for oxygen, they are also able to stay under water for long periods of time because of their ability to hold extra oxygen in muscles and in the blood Many marine mammals have an excess amount of blood and can direct it to the most important organs when necessary They can also slow their heartbeat for more efficient oxygen use when diving

• The five most common groups of marine mammals include the pinnipeds (sea lions, seals, walruses, and fur seals), carnivoras (polar bears and sea otters), cetaceans (whales, dolphins, and porpoises), and sirenians (dugongs and manatees)

• Whales are divided into the Baleen whales and the Toothed whales Both types of whales have highly developed senses, blubber to keep warm and long bodies enabling them to swim quickly Baleen whales have baleen plates instead of teeth composed of rigid fibers that act like a filter to catch zooplankton and phytoplankton The upper jaws of Baleen whales are long and flat Toothed whales and dolphins are able to use teeth to catch prey Animals like fish, octopus, squid and even other whales are swallowed whole and head first after being turned around by a powerful tongue Dolphins are different from the whales due to cone-shaped teeth, a curved dorsal fin and a lengthy rostrum Dolphins have a larger brain than porpoises and porpoises have a more rounded nose, a triangular shaped dorsal fin and spade-like teeth

• There are three families of seals which include the True seal, the Eared seal and the Walrus Although seals have blubber, they are warm blooded They can live on land or in water Seals can live out at sea for months at a time only returning to land for the mating season and to moult Seals are found all over the world in coastal areas with many nutrients The fur seals and sea lions are part of the Eared seal family These animals have large flippers in the front, tiny ear lobes and webbed back legs that can rotate around For this reason, Eared seals are capable of moving quite easily when in water or on land With no ears, short flippers and no rotation of the back flippers, True seals are easily distinguishable from the Eared seals mostly because they look very awkward when trying to move on land

Walruses have a little hair on their body but not much, long tusks and short little whiskers They are also quite a bit larger than other pinnipeds

• In the order Sirenia, there are three species of Manatees and one species of Dugong Although Dugongs have many of the characteristics

of other marine mammals, they have a higher blubber ratio Dugongs and manatees are gentle animals with oversized front flippers Manatees are characterized by a round tail and can be found in North American waters, West India, and West Africa Dugongs have a dolphin-like tail and are found in throughout Australia

• Polar bears are the largest of all carnivores that live on land and are found throughout the arctic on sea ice, islands, coastlines and in the water These amazing predators often feed on ringed or bearded seals The skin of polar bears is black and the fur is actually clear They appear off-white because of their highly reflective coat and dark skin Polar bears are protected from extreme temperatures with a thick layer of blubber and have adapted long necks and bodies for more efficient swimming