chapter 6 marine vertebrates although occupying a single subphylum, vertebrates rival nearly all...
Post on 19-Dec-2015
217 views
TRANSCRIPT
Chapter 6
Marine VertebratesMarine Vertebrates
Although occupying a single subphylum, vertebrates rival nearly all other phyla in terms of diversity and ecology. They occupy all marine habitats and are important players in nearly all marine food webs.
Copyright © 2004 Jones and Bartlett Publishers
Vertebrate FeaturesVertebrate Features
•All vertebrates possess the standard All vertebrates possess the standard chordate features as well as chordate features as well as – segmental ossification of the notochord segmental ossification of the notochord – a musculature that is segmented into a musculature that is segmented into
myomeresmyomeres– and a closed circulatory system with and a closed circulatory system with
hemoglobin contained within red blood hemoglobin contained within red blood cells that cannot leave the blood vessels.cells that cannot leave the blood vessels.
Chapter 6
Vertebrate FeaturesVertebrate Features
•Fig. 6.1 Generalized structure of a chordate.Fig. 6.1 Generalized structure of a chordate.
Chapter 6
Marine FishesMarine Fishes
•Fishes, which include about 50% of Fishes, which include about 50% of all living vertebrates, are a diverse all living vertebrates, are a diverse assemblage that is difficult to assemblage that is difficult to characterize but which usually live in characterize but which usually live in water, swim with fins, possess scales, water, swim with fins, possess scales, and use gills supplied with a and use gills supplied with a countercurrent circulation for gas countercurrent circulation for gas exchange.exchange.
Chapter 6
Marine FishesMarine Fishes
•Fig. 6.3 Phylogenetic relationships of vertebrate classes, with Fig. 6.3 Phylogenetic relationships of vertebrate classes, with emphasis on modern fish groups. Class names are in color.emphasis on modern fish groups. Class names are in color.
Chapter 6
Marine FishesMarine FishesChapter 6
Marine FishesMarine Fishes
•Agnatha—The Jawless FishesAgnatha—The Jawless Fishes– Agnathans are living jawless fishes that Agnathans are living jawless fishes that
are distinguished from other vertebrates are distinguished from other vertebrates by their lack of a jaw, paired fins, and by their lack of a jaw, paired fins, and scales. scales.
– Hagfishes are marine benthic scavengers Hagfishes are marine benthic scavengers that possess unique slime glands, that possess unique slime glands, whereas lampreys are anadromous whereas lampreys are anadromous creatures that often parasitize teleosts as creatures that often parasitize teleosts as adults.adults.
Chapter 6
Marine FishesMarine Fishes
•ChondrichthyesChondrichthyes– The sharks, rays, and chimeras of class The sharks, rays, and chimeras of class
Chondrichthyes are mostly marine Chondrichthyes are mostly marine fishes that often grow to large sizes, fishes that often grow to large sizes, retain metabolic waste products (urea retain metabolic waste products (urea and trimethylamine oxide [TMAO]) to and trimethylamine oxide [TMAO]) to achieve osmotic equilibrium with achieve osmotic equilibrium with seawater, and possess a characteristic seawater, and possess a characteristic heterocercal caudal fin.heterocercal caudal fin.
Chapter 6
Marine FishesMarine Fishes•ChondrichthyesChondrichthyes
Chapter 6
Fig. 6.9 A pelagic great white shark, Carcharodon. Lift is obtained from its herterocercal tail and the large pectorals extending from the flattened underside of the body.
Marine FishesMarine Fishes
•ChondrichthyesChondrichthyes– Chondrichthyans reproduce via Chondrichthyans reproduce via
internal fertilizationinternal fertilization– They possess internal embryos that They possess internal embryos that
develop inside egg casesdevelop inside egg cases– The egg cases are deposited in the The egg cases are deposited in the
environment or are born live after environment or are born live after completing their development inside completing their development inside their mothers, both with and without their mothers, both with and without the benefit of a placental attachment the benefit of a placental attachment to her blood supply.to her blood supply.
Chapter 6
Marine FishesMarine Fishes
•ChondrichthyesChondrichthyes
Chapter 6
Fig. 6.10 Developing swell-shark embryo, Cephaloscyllium, enclosed in a tough, protective egg case.
Marine FishesMarine Fishes
•Osteichthyes—The Bony FishesOsteichthyes—The Bony Fishes– Many thousands of species of bony fishes Many thousands of species of bony fishes
are marine, and all but one are ray-are marine, and all but one are ray-finned.finned.
Chapter 6
Marine Marine FishesFishes
Chapter 6
Fig. 6.13 Some representative body types of nine common orders of marine fishes.
Osteichthyes—The Bony Fishes
Marine FishesMarine Fishes
•Osteichthyes—The Osteichthyes—The Bony FishesBony Fishes– The only exception is The only exception is
the lobe-finned the lobe-finned coelacanth, first coelacanth, first collected in the collected in the western Indian western Indian Ocean but now Ocean but now known from known from Indonesia as well.Indonesia as well.
Chapter 6
Marine FishesMarine Fishes
•Osteichthyes—The Bony FishesOsteichthyes—The Bony Fishes– Fishes swim via thrust generated by highly Fishes swim via thrust generated by highly
coordinated movements of many different coordinated movements of many different fins and fin combinations, including fins and fin combinations, including
•lateral movements of the caudal fin, lateral movements of the caudal fin,
•flapping or undulating pectoral fins, flapping or undulating pectoral fins,
•fanning of the pectoral fins, fanning of the pectoral fins,
•or sculling movements of the dorsal and anal or sculling movements of the dorsal and anal fins.fins.
Chapter 6
Marine FishesMarine Fishes•OsteichthyesOsteichthyes—The Bony —The Bony FishesFishes
Chapter 6
Fig. 6.14 Examples of body shape specialization for three different swimming modes. Adapted from Webb 1984.
Marine TetrapodsMarine Tetrapods
•Air-breathing tetrapods that have Air-breathing tetrapods that have returned to a sometimes full-time life returned to a sometimes full-time life in the sea includes representatives of in the sea includes representatives of reptiles, birds, and mammals. reptiles, birds, and mammals.
•All are hypoosmotic to seawater, and All are hypoosmotic to seawater, and two groups are homeothermic.two groups are homeothermic.
Chapter 6
Marine TetrapodsMarine Tetrapods
•Marine ReptilesMarine Reptiles– About 100 species of sea snakes, seven About 100 species of sea snakes, seven
species of sea turtles, and one species of sea turtles, and one representative each of iguana and representative each of iguana and crocodile are truly marine (other reptiles crocodile are truly marine (other reptiles are estuarine). are estuarine).
Chapter 6
Marine TetrapodsMarine Tetrapods•Marine ReptilesMarine Reptiles
Chapter 6
Fig. 6.22 Some marine reptiles
(b) sea snake
(a) marine iguana, Amblyrhynchus of the Galapagos Islands
(c) green sea turtle, Chelonia
Marine TetrapodsMarine Tetrapods
•Marine Reptiles and BirdsMarine Reptiles and Birds– All marine reptiles, and the closely All marine reptiles, and the closely
related sea birds, eliminate excess salts related sea birds, eliminate excess salts via their kidneys and specialized salt via their kidneys and specialized salt glands contained in their mouths, glands contained in their mouths, nostrils, or orbits.nostrils, or orbits.
Chapter 6
Marine TetrapodsMarine Tetrapods
•Marine BirdsMarine Birds– “ “Marine” birds range from those that are Marine” birds range from those that are
nearly full-time residents of the sea, such nearly full-time residents of the sea, such as penguins, to other species that simply as penguins, to other species that simply visit the shoreline to feed, such as some visit the shoreline to feed, such as some ducks, geese, and coots. ducks, geese, and coots.
Chapter 6
Marine TetrapodsMarine Tetrapods
•MarinMarine Birdse Birds
Chapter 6
Fig. 6.27 Bill shapes and pursuit patterns of birds that feed at sea.
Marine TetrapodsMarine Tetrapods
•Marine MammalsMarine Mammals– Three orders of mammals can be found Three orders of mammals can be found
in the sea, includingin the sea, including•Carnivora (sea otters and pinnipeds),Carnivora (sea otters and pinnipeds),
•Sirenia (manatees and dugong), Sirenia (manatees and dugong),
•and Cetacea (whales, dolphins, and and Cetacea (whales, dolphins, and porpoises).porpoises).
Chapter 6
Marine TetrapodsMarine Tetrapods•Marine MammalsMarine Mammals– Carnivora (sea otters and pinnipeds)Carnivora (sea otters and pinnipeds)
Chapter 6
Fig. 6.31a One type of pinniped: harbor seals, Phoca.
Marine TetrapodsMarine Tetrapods•Marine MammalsMarine Mammals– Sirenia (manatees and dugong), Sirenia (manatees and dugong),
Chapter 6
Fig. 6.33 Manatee cow and calf (Trichechus).
Marine TetrapodsMarine Tetrapods
•Marine Marine MammalsMammals– CetaceaCetacea
•whaleswhales
•dolphinsdolphins
•porpoiseporpoisess
Chapter 6
Fig. 6.34 A few species of cetaceans, showing the immense range of body sizes at maturity.
Breath-Hold Diving in Marine Breath-Hold Diving in Marine MammalsMammals•All air-breathing tetrapods are All air-breathing tetrapods are capable of diving deeper and longer capable of diving deeper and longer than humans, and some species, than humans, and some species, such as elephant seals, sperm such as elephant seals, sperm whales, and emperor penguins, can whales, and emperor penguins, can dive to more than 1000 m for longer dive to more than 1000 m for longer than an hour. than an hour.
Chapter 6
Breath-Hold Diving in Marine Breath-Hold Diving in Marine MammalsMammals
•Fig. 6.40 Comparison of oxygen stores Fig. 6.40 Comparison of oxygen stores in blood (B), muscles (M), and lungs (L) in blood (B), muscles (M), and lungs (L) for several different mammals.for several different mammals.
Chapter 6
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities
•ChemoreceptionChemoreception– Chemoreception is very important to Chemoreception is very important to
marine fishes, and they may possess marine fishes, and they may possess some of the most sensitive noses of any some of the most sensitive noses of any animal.animal.
– Tetrapods all close their nostrils while Tetrapods all close their nostrils while under water and therefore rely on their under water and therefore rely on their sense of smell very little. sense of smell very little.
Chapter 6
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities•Electroreception and Electroreception and MagnetoreceptionMagnetoreception– The ability to detect weak electric and The ability to detect weak electric and
electromagnetic fields has been electromagnetic fields has been demonstrated in bacteria, demonstrated in bacteria, cartilaginous and bony fishes, some cartilaginous and bony fishes, some birds, and possibly some whales.birds, and possibly some whales.
Chapter 6
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities•VisionVision– Aquatic vision requires alterations to terrestrial Aquatic vision requires alterations to terrestrial
visual systems to compensate for the quality visual systems to compensate for the quality and quantity of light available under water.and quantity of light available under water.
– Marine vertebrates focus by moving the lens Marine vertebrates focus by moving the lens within the eye (rather than changing its shape) within the eye (rather than changing its shape) and detect light with altered ratios of and detect light with altered ratios of photoreceptor cells and unique visual pigments.photoreceptor cells and unique visual pigments.
Chapter 6
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities
•VisionVision
Chapter 6
Fig. 6.44 Cross-section of a fish eye. Note the solid, round lens that is focused by being moved toward or away from the retina by the retractor muscle.
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities
•EquilibriuEquilibriumm
Chapter 6
Fig. 6.46 Anatomical location (left) and general structure of a labyrinth/otolith organ of a bony fish.
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities
•Sound ReceptionSound Reception——FishesFishes– Most marine fishes use lateral lines Most marine fishes use lateral lines
and labyrinth organs for detecting and labyrinth organs for detecting water-borne sounds. water-borne sounds.
Chapter 6
Vertebrate Sensory Vertebrate Sensory CapabilitiesCapabilities
•Sound ReceptionSound Reception——TetrapodsTetrapods– Most marine tetrapods use anatomic Most marine tetrapods use anatomic
systems for hearing that are very systems for hearing that are very similar to those seen in terrestrial similar to those seen in terrestrial species.species.
– Because sound travels about five Because sound travels about five times faster in water, cetaceans have times faster in water, cetaceans have evolved alternative routes for sound evolved alternative routes for sound conduction to the sensory hair cells in conduction to the sensory hair cells in their cochlea. their cochlea.
Chapter 6
