Animals Taxonomy Flashcards
What are the 5 subclasses of Cnidaria?
Hydrozoa
Scyphozoa
Cubozoa
Anthozoa
Staurozoa
What are the two morphological types of Cnidaria?
Polyp: hydroid, sedentary form
Medusa: jellyfish, floating form
What is the mesoglea?
The mesoglea is an extracellular matrix located between the epidermis and the gastrodermis of Cnidarians
What is the name of the particular cell type of Cnidarians and what’s their deal?
Cnidocytes: each of them is able to produce one of over 20 kinds of distinctive organelles called cnidae (e.g. Nematocysts: inject toxin for prey capture and defence)
How does the nematocyst in anthozoans discharge?
When stimulated the high internal osmotic pressure causes water to rush into the capsule, the operculum opens, and the rapidly increasing hydrostatic pressure forces the thread out with great force.
What does the venom of cnidarians contain?
enzymes (lipolytic and proteolytic proteins that catabolize prey tissue),
pore forming toxins and neurotoxins
Hydrozoa
mainly remain in polyp forms and create colonies. When present, medusae are small, and the mouth opens at the end of a manubrium
Scyphozoa
large jellyfish, velum absent, the manubrium usually forms 4 oral arms
Staurozoa
solitary polyps attached to the sea bottom, with the top resembling a medusa with eight
extensions
Cubozoa
the predominant form is medusoid, the bell is almost square with a tentacle or a group of
tentacles at each corner
Anthozoa
there is no medusa stage and may be solitary or colonial. This class contains 3 subclasses:
1. Hexacorallia: are the sea anemones and corals. Sea anemones can glide along a substrate, expand and stretch their tentacles and “swim” by rhythmical bending movements. Scleractinia (true or stony corals) live in calcareous cups in which polyps can retract.
2. Ceriantipatharia: are tube anemones (solitary and found in soft sediments) and thorny corals (are colonial and attached to a firm substratum)
3. Octocorallia: are soft and horny corals, such as sea fans, sea pens, sea pansies, and others
What are organs of equilibrium in invertebrates (e.g. cnidarians)?
statocysts
What are ocelli?
Light sensitive organs in Cnidaria
(not in Staurozoa)
(also in Platyhelminthes, Annelids, Molluscs, Echinodermata, Arthropoda)
In Scyphozoa and Cubozoa, there are different sensory organs called?
- Rhopalia
- Each rhopalium is club-shaped
- Each rhopalium contains a hollow statocyst for equilibrium
- In some species the rhopalia also bear ocelli
- In Cubozoa each rhopalium houses 6 eyes in addition to other sense organs (instead of ocelli)
How does the asexual reproduction in cnidarian occur?
budding
(hydrozoa,anthozoa)
How does the sexual reproduction in cnidarians occur?
By gametes and its present in all medusae and in some polyps
eggs and sperm released in water
In case of sexual reproduction: What is the larvae of cnidarians called?
planula
How do cnidarians feed?
They are all carnivorous and actively preying
What are zooxanthellea?
Mutualistic dinoflagellates of Cnidarians:
- photosynthesis and fixation of carbon dioxide –>provide for hosts
- recycle phosphor and nitrogen
- enhance ability of coral to deposit calcium carbonate
- require light
What are the two types of frameworks in Porifera?
Rigid: calcareous or siliceous structures called spicules
Fibrous: collagen fibrils present in the intercellular matrix. One form is called spongin.
What is the osculum in Porifera?
the point where the water exists the internal canals
What is the name of the typical cell form in Porifera and how are the three systems called according to the position of these cells?
Choanocytes:
1. Asconoid system: the choanocytes lie in a large chamber (Calcarea)
2. Syconoid system, the choanocytes lie in canals (Calcarea, some Hexactinellida)
3. Leuconoid system: the choanocytes lie in distinct chambers. This system has the highest proportion
of flagellated surface area for a given volume of cell tissue.
What do we mean with somatic embryogenesis in sponges?
Entire new sponges can develop from small fragments
How does the asexual reproduction occur in Porifera?
bud formation
External buds, after reaching a certain size, detach from the parent and float away to form new sponges, or they can remain to form colonies. There are also internal buds, called gemmules which remain dormant until the parent animal dies. This is a way of preserving the species during periods of freezing or drought.
how do Sponges produce sexually?
- some are hermaphroditic
- some are gonochoristic
What are the names of Porifera larvae?
solid-bodied, free swimming: parenchymula
not solid-bodied: amphiblastula
How do Porifera feed?
They are suspension feeders
Why do sponges have very few predators?
noxious odor (aka they stink) and elaborate skeletal framework that have antipredator effects
How is the body of Ctenophora composed?
It is composed by 8 rows of combs radially arranged around the body
How do Ctenophores locomote?
They use beating cilia for locomotion
How do Ctenopohores catch prey?
they use colloblasts which are adhesive cells
What cells are present on the epidermis of Ctenophores and what do they do?
Sensory cells which detetct chemicals and other stimuli
What are the free-swimming larva of Ctenophores called?
cydippid
What does the nervous system of Ctenopohores consist of?
A subepidermal plexus concentrated around the mouth and beneath the comb plate rows
What is the only free-living organism class of Platyhelminthes?
Turbellaria
Other classes:
Trematoda (endoparasite)
Cestode (endoparasite)
Monogenean (ectoparasite)
Describe the sensory system of Plathyelminthes
- pair of anterior ganglia
- nerve cords
- nerves
(located in the mesenchyme) - statocysts
- ocelli
Reproduction Platyhelminthes
Asexual: fragmentation
Sexual: cross or internal fertilisation (hermaphroditic, not all!)
What is the intermediate and the final host of Trematoda?
Trematoda: class of platyhelmintes
Molluscs usually represent the intermediate host, while vertebrates present the final host
What is specific about the Tubellaria eggs?
After copulation, the fertilised eggs become enclosed in a small cocoon. The cocoons are attached to stones or plants and embryos emerge as juveniles, which also resemble the mature adults
3 classes of Nemertea
Haplonemertea
Paleonemertea
Pilidiophora
Which Phylum has a Proboscis?
Nemertea
What is a Proboscis?
The proboscis is a long, blind muscular tube that opens at the anterior end at a proboscis pore above the mouth. Its function is in capturing prey: Muscular pressure fluid in the rhynchocoel causes the proboscis to evert rapidly. This exposes a sharp barb called stylet, with which the prey is stabed and inserted with toxins after being coiled around by the proboscis.
in ALL nemertea
What communicates between the outside and the brain in Nemertea?
Sensory ciliated pits on each side of the head
Reproduction Nemertea
Asexual: fragmentation & regeneration
Sexual: gonochoric, fertilisation often external but many exceptions are known
What do Nemerteans eat?
Predators of annelids and other small invertebrates
What are the 2 classes of Nematoda?
Phasmida
Aphasmida
What is the hydrostatic skeleton in Nematoda?
fluid-filled pseudocoelom: internal organs lie here
How is the high hydrostatic pressure (tugor) in Nematoda contained?
- non-cellular cuticle presents several layers of collagen (outer layer)
- cuticle for hydrostatic pressure
- fluid-filled pseudocoel constitutes hydrostatic skeleton
Describe the sensory system of Nematoda
- ring of nerve tissue + ganglia
- small nerves
- 2 nerve cords
- Sensory papillae (taste)
- amphids: anterior, smell
- phasmids: posterior, directional movement away from substrate
What phylum has copulatory spicules, smaller males than females and are gonochoric?
Nematodes
How many juvenile stages do nematodes have?
4 juvenile stages, separated by a molt /shedding of cuticle (some need host for specific stages)
What secretes the shell in Mollusca and encloses the mantle cavity?
The mantle
What is the radula?
A rasping organ in the Mollusca
How do molluscs exchange gas?
Gills, lungs, mantle or body surface
Do Molluscs have a closed circulatory system?
no, its open
How many chambers does a mollusc heart have?
3
Name the 3 layers of the shell (Mollusca)
- Periostracum: outer organic layer, composed of an organic substance called conchiolin. It helps to protect underlying calcareous layers from erosion.
- Middle prismatic layer: composed of densely packed prisms of calcium carbonate.
- Inner nacreous layer: lies next to the mantle and is secreted continuously by the mantle surface, so that it increases in thickness during the life of the animal.
What sensory organs do Mollusca have?
Touch, smell, taste, equilibrium and vision
Is there asexual reproduction in Mollusca?
No
Larvae types in mollusca
and annelida
free-swimming trochophore larva
(NOT CEPHALOPODS)
Peculiarity of Caudofoveata (class of Mollusca)?
-oral shield
-no shell, but covered in calcareous sclerites
Peculiarity of Solenogaster (class of Mollusca)?
foot is represented by a mid ventral structure called pedal groove
Peculiarity of Polyplacophora (class of Mollusca)?
- chitons
- 7/8 plates or valves
- osphradia for sampling water
Peculiarity of Gastropoda (class of Mollusca)?
-univalve
-respiration by organ called ctenidium
-one nephridium
-well developed circulatory system
What is an osphradium?
A sensory area in Gastropods, located at the base of the incurrent siphon and can be chemosensory in some forms or mechanoreceptive in some others.
What is the offspring of Gastropoda?
veliger larvae
Mantle cavity in Prosobranchs
In Prosobranchs the mantle cavity is anterior as a result of torsion that occurs during the development
How are the two valves in bivalves held together?
hinge ligament, drawn together by adductor muscles (zieht zsm) that work in opposition to the hinge ligament
What is umbo?
The umbo is the oldest part of the bivalve shell, and growth occurs in concentric lines around it.
-one umbo on each valve
Sense organs in bivalves
poorly developed: they include
- a pair of statocysts in the foot
- a pair of osphradia in the mantle cavity
- tactile cells
- simple pigment cells on the mantle
how can bivalves attach to the substrate?
byssus, a secretion made of keratin and other proteins.
Bivalve reproduction
Bivalves are usually gonochoric. Gametes are discharged into the suprabranchial chamber to be carried out with the excurrent flow. In most bivalves fertilization is external and the embryo develops into trochophore.
Nautilus shell
The shell is divided by transverse septa into internal chambers, only the last inhabited by the living animal. The chambers are connected by a cord of living tissue called a siphuncle, which extends from the visceral mass.
How do cephalopods swim?
Force full expulsion of water from the mantle cavity through the ventral funnel (or siphon) creates jet propulsion
Molluscan circulatory system
open circulatory system of
1. heart
2. blood vessels
3. sinuses
4. resparatory pigments in blood
Which animal has giant nerve fibres?
Squids
How to chromatophores work?
Chromatophores are cells in the skin that contain pigment granules: tiny muscle cells surround each elastic chromatophore, whose contractions causes the chromatophore to expand greatly. As the cell expands, the pigment becomes dispersed, changing the color pattern of the animal. When the muscles relax, chromatophores return to their original size, and pigment becomes concentrated again.
What is a protective feature of most cephalopods ?
ink sac containing sepia
What is a hectocotylus?
One arm of adult male cephalopod is modified as an intromittent organ, called a hectocotylus, used to insert spermatozoa into the mantle cavity of a female near the oviduct opening. Eggs are fertilized as they leave the oviduct and are then usually attached to stones.
Do free-swimming larva exist in cephalopods?
no, juveniles hatch from eggs
How do cephalopods feed?
They are active predators, with the help of arms provided with suckers and beak for crushing the prey
3 classes of Annelida
Polychaeta
Oligochaete
Hirudinea
Where do the toxins in molluscs or annelids come from?
Mostly nematocysts of cnidarians the animals have fed on and then stored the undischarged nematocysts in their own tissue (e.g. fireworm)
What is a metameric body?
A body structure composed by segments, like the one of annelids
How does the gas exchange occur in annelids?
Through skin, gills, or parapodia
Circulatory system of annelids
- circulatory system is closed
- muscular blood vessels
- aortic arches (like hearts) for pumping blood
- segmentally arranged.
Do annelids have eyes?
Some species have eyes yes. They can vary from eyespots to well-developed organs with lenses
Annelid reproduction
- asexual: fission (split in 2) and fragmentation
- sexual: gonochoric or hermaphroditic
- trochophore larvae
Palolo worms reproduction
- most of the year as sexually immature animals
- breeding season: portion of the body becomes sexually mature
- that part is then full of gametes
- reproductive period: sexually mature portions (=epitokes) break off and swim to the surface
- release of epitokes is highly synchronous
- freeing eggs and sperm for fertilization
- Anterior portions of the worms remain on the bottom and regenerate new posterior sections.
- they are hermaphroditic
What are the sexually mature portions in palolo worms called?
epitokes
What feeders are errant worms like the fireworm?
Predators and scavengers
What part of the fireworm contains a poisonous secretion?
The setae (hair-like structure)
What are the two main subphyla we looked at in the Arthropoda?
Chelicerata & Crustacea
What is a characteristic of arthropoda?
jointed appendages, which are often modified for specialised functions
What are the functional groups (tagmata) of arthropoda?
- Head and trunk
- Head, thorax and abdomen
- Cephalothorax and abdomen
To what nervous system is the one of Arthopods similar to?
Annelids
- dorsal brain connected to
- a double nerve chain of
- ventral ganglia
In which taxa do we observe parthenogenesis (egg development without fertilisation)?
Arthropoda
class: Malacostraca
What are the two main species inside the subphylum of chelicerate?
sea spiders & horseshoe crabs
What are the tagma of Horshoe crabs (Xiphosaurids)?
Cephalothorax & Abdomen
What are the gills of horseshoe crabs called?
Book gills
What is a unique feature of sea spiders?
They have a feature unique among arthropods: segments are duplicated in some groups, so that they possess five or six pairs of legs instead of the four pairs. Males of many species bear a subsidiary pair of legs called ovigers on which they carry eggs.
What are the tagmata of Malacostraca (shrimps)?
Cephalothorax , rostrum & telson (both unsegmented)
What are ommatidia?
photoreceptor units that make up anele (e.g. in malacostraca) A transparent area of cuticula (called cornea) covers the surface of each eye and cornea is divided into many small squares known as facets. These facets form the outer faces of the ommatidia. Each ommatidium behaves like a tiny eye.
ChatGPT:
Ommatidia are like tiny units in a shrimp’s eye, kind of like pixels in a digital image. Each ommatidium is a small, individual visual receptor that helps the shrimp see its surroundings. Shrimp have many ommatidia packed together in their compound eyes, which allows them to detect movement and see different colors and shapes. This compound eye structure gives shrimp a wide field of view and helps them spot predators and prey in their environment.
What are statocysts for?
Organs for equilibrium
What are tactile hairs?
in Malacostraca widely distributed over the body, are delicate projections of cuticle that are especially
abundant on the chelae, mouthparts, and telson
- also known as setae
- serve as mechanoreceptors, detecting touch and vibration in the surrounding environment
What is the larvae called in Malacostraca?
Naupilus
What is ecdysis?
The process of shedding in crustacea.
Molting on the other hand is the physical process of producing a larger cuticle
Why do crustaceans have molting and ecdysis?
Exoskeleton is nonliving and doesn’t grow
What is the name of the walking legs in crustacea?
- Chelipeds
(also for food capturing) - first one usually larger then others, also for capturing prey or defense
- first ones are often asymmetrical
How do barnacles feed?
they use their legs, which bear a thick fringe of setae, to create water currents that sweep food
Branchiopoda fun fact
they have flattened and leaflike legs that serve as respiratory organs (hence the name branchiopods). Most branchiopods also use their legs for suspension feeding, and for locomotion as well.
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Branchiopoda
Body symmetry of echinodermata
pentaradial with unique water-vascular system
How is the locomotion in echinodermata achieved?
tube feet, movement of spines, or by movement of arms, which project from central disc of body
How is the nervous system of echinodermata?
any receptors maybe?
- circumoral ring
- radial nerves
- No brain
- specialized sensory organs as:
- tactile receptors
- chemoreceptors
- terminal tentacles
- photoreceptors
- statocysts
What are Asteroidea (Seastars) composed of?
central disc, 5 arms (or more) emerging, mouth is centred under oral side
What are podia?
tube feet that border the ambulacral groove in Asteroidea
What can we find around the bases of spines of Asteroidea?
- groups of pincerlike pedicellariae
- bearing tiny jaws manipulated by muscles
- jaws keep the body surface free of debris
- protect papulae
Papulae
- soft projections of the coelomic cavity
- covered only with epidermis
- involved with respiration
- (also called skin gills)
How do sea stars catch prey?
Stomach can be everted through the mouth
Do Ophiuroidea (brittle star) have pedicellariae or papulae?
- No, but seastars
- picture: papulae on abural surface (nach oben gerichtet)
- pedicellariae are specialized structures involved in defense and protection
- papulae are specialized for respiratory function and gas exchange
Do Ophiuroidea have suckers on their feet?
No
How do Ophiuroidea locomote?
with their arms
Where are the visceral organs in Ophiuroidea?
In central disc, because arms are to slender
How does gas exchange happen in Ophiuroidea (Brittle stars)?
- Structures called bursae open toward the oral surface
- water circulates in and out of these sacs for exchange of gases
- On the coelomic wall of each bursa there are small gonads
- they discharge sex cells into the bursa
- Gametes then pass into the water for fertilization.
Are brittle stars positive or negative phototroph?
Negative (move away from light)
What is the fancy word for sea urchin?
Echinoidea
What do sea urchins and sea stars have in common?
pentamerous plan: the five pairs of ambulacral grows are homologous to the five arms of sea stars
What is the Aristotle’s lantern?
Complex chewing mechanism in sea urchins to which teeth are attached
What is the fancy word to sea cucumber and to which phylum does it belong?
Holothuroidea –> Echinodermata
What is the side applied to the substratum in sea cucumbers called?
sole(?)
ventral side oder?
What is a tegmen?
The skin that covers the body disc in sea lilies (Crinoidea, Echinodermata)
What do all organisms in the super phylum chordata have in common?
bilateral symmetry
3 germ layers
coelom
notochord (at least in some life stages)
nerve cord (single, dorsal, tubular)
complete digestive system
What are the 3 particular phyla found in chordata?
Urochordata (Tunicata)
Cephalochordata
Vertebrata
What is the mantle in Tunicata?
The inner membrane
What are the names of the two siphons found in Ascidian (Tunicata)?
Incurrent/oral siphon: corresponds to the anterior end of the body
Excurrent /atrial siphon: marks the dorsal side
–> In compound ascidians each member has its own incurrent siphon, but the excurrent opening is common to the group
On what does feeding depend in Ascidians?
Feeding depends on formation of a mucous net secreted by a glandular groove, the endostyle, located along the pharynx.
Of what does the circulatory system in Ascidiae (Tunicata) consist and how is the blood flow?
circulatory system:
- ventral heart
- two large vessels
- the heart drives the blood first in one direction for a few beats
- then pauses
- reverses its action
- drives the blood in the opposite direction for a few beats.
What does paedomorphic mean?
sexually mature animals that have retained the larval body form of their evolutionary ancestors
(e.g. Appendicularia / Urochordata)
What Urochordata has a luminous organ?
Thaliacea
What are the five distinctive characters of chordates that Cephalochordata have in simple form?
- digestive system
- circulatory system
- nervous system
- simple sense organs simple (including anterior ocellus, functioning as photoreceptor)
- Sexes are separate
- fertilization is external
- Larvae hatch soon after egg deposition and gradually assume the shape of adults.
What do all vertebrate morphologically show?
- outer & inner dermis
- bone endoskeleton (vertebra & head)
- muscle segments / myomeres
- muscularized digestive tract
- closed blood vessel system of arteries, veins and capillaries
- highly differentiated tripartite brain
- gonochoric (separate sexes)
Why is the Hagfish (Myxini) a subphylum of the Agnatha?
No jaws
(Hagfish = Schleimaal)
(Agnatha = Kieferlose)
Are Hagfish (Myxini) isosmotic?
Yes
Are Petromyzontida (Lampreys) part of the Agnatha?
- yes
- they also are anadromous
What does anadromous mean and which class is it?
born in seawater, spend their parasitic life in freshwater and then return in seawater to reproduce
Ex: Petromyzontida
How are the modified pelvic fins in male Chondrichthyes called?
Claspers
How do Chondrichthyes manage buoyancy?
Chordata-Vertebrata-Chondrichthyes (Knorpelfische)
oil-filled liver
Circulatory system of Chondrichthyes
- Several pairs of aortic arches (they have single circulation)
- Heart is composed by
1. sinus venosus
2. atrium
3. ventricle
4. cornus arteriosus
Are four pairs of gills covered by an operculum in chimaeras?
Yes
Do Chondrichthyes have a swim bladder or a lung?
No, but they have ophisthonephric kidneys
and gills
How do Chondrichthyes reception vibration?
By their lateral-line system
What are the reproductive modes of Chondrichthyes?
oviparous, ovoviviparous or viviparous
Is the development in the Chondrichthyes direct?
Yes, in any reproductive mode
What animal is this?
Chimaeriformes, subclass of Chondrichthyes
What does the flashy operculum in Chimaeriformes cover?
The gills
What is the eye-adaptation to their deep water habitat in Chimaeriformes?
Large eyes and rods
Can also present a tapetum lucidum that reflects the light to improve vision in deep-water.
What is the tube pattern on the surface of the skin in the head region of Chimaeriformes (= Seekatzen <3)?
distinctive mechanosensory lateral line canal system
The also have many electro receptive ampullae
What does the shape of eggs in Chondrichthyes represent?
Egg capsule is characteristic for each family
How long does the embryo development in Chimaeriformes last?
9-12 months
What do males as sexual dimorphism represent in Chimaeriformes?
sexual dimorphism:
- claspers,
- frontal tenaculum (sharp denticles to grasp pectoral fins of female during copulation)
- paired pre-pelvic tenacula
What do Chimaeriformes eat?
Benthic invertebrates and small fishes (tooth plates allow crushing)
What are the three main body shapes of subclasses in Elasmobranchs?
Sharks, skates and rays
What is the spiracle, present in Elasmobranchs?
- provides oxygenated blood directly to the eye and brain through a separate blood vessel
- Rays present larger spiracles to actively pump water over the gills to allow the ray to breathe while buried in the sand.
How can you distinguish the sex in Elasmobranchs?
Males have elongated an calcified claspers at sexual maturity
Females are larger in several species
How are embryos nourished in viviparous species?
by yolk only (ovoviviparity), uterine secretion (“uterine milk”) or by placenta.
Why are Elasmobranchs endangered?
Due to their large size and depending on the depths they live in, they are easy targets (commercially valuable).
Since this animals are top predators, their absence influences the whole trophic web.
Do sharks have an operculum?
No
Difference in fertilisation between Condrichtyhes and Osteichthyes
(Knorpel- vs. Knochenfische)
Internal fertilisation in Chonrichtyhes vs external fertilisation in Osteichthyes (of course there are exceptions)
Which is the bigger and the smaller subclass of Osteichthyes?
Bigger: Actinopterygii (Strahlenflosser)
Smaller: Sarcopterygii (Fleisch- / Muskelflosser)
What are the different types of scales in Actinopterygii?
- Ganoid in ancestral forms, scales cycloid
- Ctenoid or absent in derived forms
Fins of Acinopterygii
They have paired and median fins supported by long dermal rays called lepidotrichia. The muscles controlling fin movement are within body and fins can present modifications.
- median fins: dorsal, anal and caudal
- paired: pectoral and pelvic
Do Actinopterygii have jaws?
Yes
Are the gills in Actinopterygii covered?
Strahlenflosser, Klasse der Knochenfische
Yes, by an operculum
Do Actinopterygii have a swim bladder?
Yes, often, most
for buouyancy
What is different in Actinopterygii to Chondrichthyes concerning the olfactory lobes?
- both located in forebrain
- in Actinopterygii: don’t open into the mouth cavity
- Olfactory lobes are regions of the brain that are involved in processing olfactory (smell) information
Do Actinopterygii hear?
Yes
What is the name for eggs that are attached to a substrate vs. free-floating eggs?
Demersal & pelagic
Who does more parental care in Actinoperygii?
Usually males show more parental care
Marine Actinopterygii are mostly….
Teleost
(echte Knochenfische)
Diadromous fish ?
Fish migrate during their life-cycle.
Anadromous: hatch and and reproduce in freshwater, maturate in marine waters
Catadromous: hatch and reproduce in saltwater, maturate in freshwater
What is the main difference from Sarcopterygii to Actinoperygii?
swim-bladder is fat-filled in some Actinopterygii
Which are the two orders that marine reptiles are divided in?
Squamata (sea snakes)
Testudines (sea turtles)
How does respiration in marine reptiles occur?
- Primary by lungs (they have no gills)
- cloaca
- pharynx
- skin
Circulatory system in marine reptiles is functionally divided into…
…pulmonary and systemic circuits
How do marine reptiles regulate their body temperature?
They are ectothermic (=water temperature), but many can thermoregulate behaviourally
What does the excretory system of Marine reptiles consist of?
metanephric kidneys that produce uric acid
Is there an aquatic larval stage in marine reptiles?
No
What does the distribution of Squamata (sea snakes) limit to coastal areas?
They need to drink fresh water
Are sea snakes venomous?
- yes, the majority is
- they can produce different toxins
What is the reproductive system of sea snakes?
- they are viviparous –> no eggs
- they reproduce every second year with a clutch size that increases with the size of the female
What acts as mechanoreceptors in Squamata (sea snakes)?
scale sensilla
What do sea snakes feed on?
Fish (and small little Minnes and Melina’s ham ham)
What are Testudines (marine turtles) characterised by?
- large adult body size
- hypertrophied forelimbs called flippers
- streamlined shells
Why can’t the ribs not be responsible for respiration in marine turtles?
Because they are incorporated in the shell, instead the two abdominal muscles are involved
What is a Rhamphotheci?
- keratinized covering on the beak or bill
- aiding in feeding and protection
Can sea turtles perceive sounds?
yes
How do sea turtles find back to their natal beaches?
They use geomagnetic sensing and chemoreception like the Jacobson’s organs
What species is temperature sex-determined? (TSD)
Sea turtles. They are oviparous, lay there eggs buried in the sand and above a certain temperature threshold the sex is female
Do different species of sea turtles have different diets?
Yes, can range from seagrasses, to jellyfish, to crabs and other hard-bodied invertebrates
The body of marine birds is divided into?
Head, neck, trunk and tail
What defines a marine bird?
A bird which feeds in the sea
What do marine birds have at the end of their tails?
oil or preen glands
Do marine birds have teeth?
no
How do marine birds regulate their body temperature?
endothermic (=stays the same)
How do marine birds breathe?
Respiration occurs by lungs and thin air sacs
What is the syrinx?
The voice box of marine birds, located near the junction of trachea and bronchi, important for sound production
Marine bird reproduction
They lay amniotic eggs with much yolk and hard calcareous shell. Young can be formed and independent at hatching (called precocial) or helpless and naked (called altricial).
How is the sex determined in marine birds?
By chromosomes (same as in humans, just that females are heterogametic XY)
How do marine birds deal with the high physiological salt loads that comes through their feeding?
They have salt glands, an extra-renal kidney located in the orbit of the eye
How do marine birds keep buoyancy?
Their feathers help
Why do seabirds life in colonies?
There is a positive relationship between colony size and feeding distance (so larger the number of the animals in the colony and higher is the feeding distance covered)
What do seabirds feed on?
- Small pelagic fish
- Crustaceans
- Mollusks
What’re the 3 big orders of Marine mammals?
Carnivora
Cetacea
Sirena (Sea cows)
What is the blubber in marine mammals?
It is a layer of fat cells that insulates the animal , its thicker in Cetaceans
What are the characteristics of marine mammals?
Body is covered by hair, they have mammary glands with which they feed their pups, diphyodont teeth (milk and adult set of teeth) & heterodont (vary in structure and function).
Are marine mammals endothermic (keep their body temperature)?
Yes
What animals belong to the order of Carnivora?
Pinnipedia: Fur seals & sea lions, walruses, true seals
Fissipedia: sea otters, polar bears
What is the outermost layer of the epidermis in Carnivora called?
stratum corneum
How many layers of hairs do Carnivora have?
2:
- Outer protective guard hairs
- Inner soft underfur hairs
How do pinnipeds manage to dive so deep for so long?
They exhale before diving and their lungs collapse. Through that they avoid the need for respiratory structures and avoid gas absorption. Muscle activity is maintained anaerobically, the concentration of lactates increase.
The expanded aortic bulb ( aortic arch) increases lung perfusion during the surface recovery.
What is special about the eyes of Carnivora?
The eyes exhibit adaptations for both aquatic and terrestrial habitats, are large and protected by a highly keratinized corneal epithelium. The choroid is highly vascularized and contains the tapetum lucidum, to increase the light sensitivity by acting as a mirror.
Harderian glands: located in the outer corners of the eyes producing oil to prevent eyes from drying
Is the olfactory system in marine Carnivora more or less developed than in terrestrial?
Less, but they hear like terrestrial ones
Where do pinnipeds give birth?
Out of the water
How long is between copulation and birth in pinnipeds?
Nearly one year
What are the two sub-orders of Cetaceans?
Odontocetes (dolphins)
Mysticetes (whales)
What is the feeding apparatus of Mysticeti?
plates of baleen with which the feed on planktonic items
What is the difference concerning they dive strategies in pinnipeds and cetaceans?
Pinnipeds dive with empty lungs, while cetaceans typically dive with air-filled lungs
Who has a hypertrophy of the auditory region?
Cetaceans, esp odontocetes
How do Cetaceans produce sounds?
Sound production is associated with the nasal passages. The clicks are produced by pressurization within intranasal spaces and then, as air is forced between the phonic lips, there is vibration. Periodic opening and closing of the phonic lips break the airflow and determines the click repetition rate.
What is jaw hearing?
Good hearing abilities in cetaceans, related to a unique sound reception pathway in odontocetes, commonly referred to as “jaw hearing.” Fat body that directly connects with the lateral wall of auditory bulla of the middle ear.
lower jaw acts as a pathway for sound vibrations to reach the inner ear
What is the fruity structure specifically related to echolocation in Cetaceans?
The melon 🍉 a mass of adipose tissue on top of the skull
Where do cetaceans mate and give birth?
In the water, one pup each time (10-13 months)
Who has longer migration routes in the class of cetaceans, mysticetes or odontocetes?
Mysticetes
