Animals Behaviour & Anatomy Flashcards
(116 cards)
1
Q
What are primary swimmers?
A
Invertebrates and fish
2
Q
What are secondary swimmers?
A
Marine reptiles and birds
3
Q
What are the 3 main issues for both, primary and secondary swimmers?
A
- Buoyancy
- Drag reductions
- Maintenance of orientation and direction
4
Q
Marine organisms are denser than water, how do they cope with the problem of buoyancy?
A
- through reduction of their density
- continuous movement
1. when negative buoyant –> propulsion (some fish and cephalopods) - static or dynamic buouyancy
5
Q
What examples are there for static buoyancy control?
A
- Reduction of heavy tissue
- Inclusion of low specific gravity substances: lipid, oil
6
Q
What examples are there for dynamic buoyancy control?
A
- Swim bladder (functions as a hydrostatic organ: also plays a role in respiration, sound production and sound reception)
- In Nautilus through differential chamber filling
- In surfing snails the secretion of a mucous bubbles to “surf” at the water surface
7
Q
What do we know about the swim bladder?
A
- in all Teleost
- gas-filled sac (CO2, O2, nitrogen)
- functions as hydrostatic organ
- involved in gas release and gas addition
- in some Actinoperygii they are filled with oil
8
Q
How much more denser and more viscous is water than air?
A
Water is about 800 times denser and 50 times more viscous than air. Locomotion through this dense, viscous medium is energetically expensive.
9
Q
The most energetic costly factor in locomotion is drag. What two different types of drag are there?
A
- viscous or frictional drag: it involves friction between the fish’s body and the surrounding water; as a consequence, this drag depends on the surface: total area and smoothness;
- inertial or pressure drag caused by pressure differences that result from displacement of water as the fish moves through it; it depends on the body shape and increases with the speed.
10
Q
What is a convergent evolution of teleost and elasmobranchs?
A
Streamlined body shape
11
Q
What is a tradeoff between hydrodynamic shape and?
A
e.g. reproductive success
12
Q
Hydrodynamic shape
A
- width/length=0.25
- max width at 2/5 of the body
- fins folded in grooves or depressions –> maintain the streamline
- reduce the surface
- smooth surface: mucous secretion, compact fur
13
Q
What reduces drag?
(3 things, one goes hand in hand with other)
A
- hydrodynamic shape
- smooth surfaces(mucous , compact fur)
- types of scales (reduction of vortices formation)
14
Q
Jet propulsion
A
- method of aquatic locomotion
- animals fill a muscular cavity and squirt out water to propel them in the opposite direction of the squirting water
- the force of water expulsion determines speed
- usually used together with other locomotion modes, by species like cephalopods (squids, cuttlefish, octopus), jellyfish.
15
Q
What are the two swimming types (lots of intermediates)?
A
UNDULATION
OSCILLATION
16
Q
What is the Lateral force and thrust in swimming behaviour of fish?
A
- lateral push excepted on water during movement
- reactive force can be divided into the two components
1. lateral force
2. thrust - adaptation for effective swimming:maximization of thrust respect to lateral component.
–> there is an optimal angle: ca 18°
17
Q
What do good swimmers present ?
A
- hydrodynamic shape
- stiff vertebral column
- tips of caudal fin pointed
- caudal peduncle flattend
- keels (reducing drag or adding propulsion force)
18
Q
Formula Aspect ratio
A
Aspect ratio = height2/surface area
- good swimmers = high aspect ratio: large caudal fin height and small surface
- from <1 up to 10
19
Q
What are adaptations for a rapid acceleration from a standing start?
A
- posterior propulsive elements
- large dorsal and anal fins
- placed far to the posterior
- caudal peduncle is deep
- tail has a relatively high aspect ratio (but lower than that fast swimmers like tunas)
- maximum thrust in the tail region
20
Q
What are finlets?
A
- adaptation for swimming
- prevent vortices from developing in water moving from the median fins and body surfaces towards the tail
- allows the tail to push against less turbulence
21
Q
With what habitat are keels associated in sharks?
A
Pelagic habitats
22
Q
Different tail shapes of sharks
A
23
Q
What is an adaptation in terms of temperature regulation to maintain high swimming capabilities?
A
Maintaining high (body) temperatures, higher then environmental temperatures –> e.g.Tuna
24
Q
How can thermoregulation be accomplished?
A
- Behavioural : moving to warmer areas
- Physiological: red muscles (Tunids & Lamnid sharks) –> counterurrent system: cooler blood encounters warmer blood before reaching the bulk of red muscles in the middle of the body, so higher body temperature can be maintained
25
What convergences present Tunis and Lamnid sharks?
- streamlined body shape
- lunate shape of caudal fin
- ram ventilation (saves energy)
- negative bouyant
- high aspect ratio
- bulk of red muscle in the middle of the body (teardrop body shape & stiff-bodied swimming)
26
Adaptations of good swimmers to reduce energetic costs
- ram ventilation instead of buccal pump
- high gill surface
- high concentration of haemoglobin
27
Why do some fish swim in schools?
1. Antipredatory
2. Feeding
3. Swimming (minimizes vortices formation)
28
What are adaptations of fish that live in complex environments such as coral reefs?
- shape typically laterally compressed
- tall body to ensure high maneuverability
- oscillation or undulation of dorsal, anal or pectoral fins
- 65% uses labriform swimming mode
- speed depends on shape of pectoral fins
- pectoral fin aspect ratio correlates with water velocity
- speed is correlated positively with the aspect ratio in species belonging to different families
29
speed, cruising efficiency, rapid acceleration, maneuverability are things that shape the body, caudal fin etc. and reflect performances of the fish
30
Swimming modification examples of fish
- walking on pectoral fins
- boxfish can only use pectorals
- electric field
31
Modification of pectoral fins that allow movement on land
- Pectoral fins have a robust proximal
part, while distal part allowing the
support.
* Pectoral girdle is robust.
32
What can we say about secondary swimmers?
- use mainly flippers and are good in maneuverability but only a few are fast swimmers
- forelimbs are deeply modified to function as oars. They are used to maintain the balance.
- Joints are lost, stylopodium and zeugopodium are reduced and autopodium is stretched.
33
Pitch, yaw and roll need to be limited in order to maintain swimming performances (orientation and direction). How is this achieved?
Pair and unpair fins help in balancing the animal.
Roll is hindered through pectoral and unpair fins
Yaw is hindered by a rigid head and body shape and rigidity.
34
What are the three main feeding types in the marine environment?
- Suspension feeding
- Deposit feeding
- Active or passive feeding
35
trophic web
36
Why is a first spiny ray a defence mechanism ?
Because prey has to be ingested head first
37
List prey defences
- first spiny ray
- inflating body
- toxic substances (Cuvierian organ)
- camouflage
- aposematic colorations (alert toxicity)
- schooling (Dilution & confusion effect)
38
List mechanisms for prey capture
- toxic substances to stun prey
- Electric shock
- Head adaptations (e.g. hammerhead)
- Teeth / gill rakers to grab prey
39
Where is the mouth of fish positioned in relation to what they feed on ?
* Superior if fish feed on preys above them
* Terminal if preys on fish in front of them
* Inferior if feed on fish below them
40
What is the development of sensory organs dependant on ?
habitat, the type of preys, the life style
--> species preying in the water column usually rely more on vision, species preying on benthic species hidden in the bottom rely more on chemosenses
41
Sensory system parts in the brain
42
Differences in sensory systems concerning habitat
43
Reef associated bentho-pelagic fishes have more developed telencephalon
--> Right or wrong?
Right
44
Cerebellum foliation index tends to be higher in pelagic and oceanic species
--> Right or wrong?
Right
45
Olfactory bulbs (OB) large in bathyal species (this is common also in teleosts).
--> Right or wrong?
Right
46
OB small in species associated with coral reefs (vision is more important)
--> Right or wrong?
Right
47
OB smaller in coastal/oceanic species (Carcharodon carcharias, Prionace glauca, Galeocerdo cuvier, Carcharias taurus), they perform also migrations.
--> Right or wrong?
Wrong, larger OB
48
Use of different sensory organs
49
What are the phases in hunting concerning the sensory system?
1. Initially detecting and evaluating cue(s) that alert the hunter to the presence of prey somewhere,
2. Tracking the cues to the vicinity of their source
3. Orienting to the prey with direct sensory contact
4. Striking at the prey, and coordinating strike behavior with jaw and/or appendage motion to capture
it
50
Why can cuttlefish change their skin coloration and pattern so fast?
- Cuttlefish are capable of rapidly changing their skin coloration and pattern through a process known as "chromatophore expansion and contraction."
- chromatophores can expand or contract in response to neural signals from the cuttlefish's brain
- When the nervous system sends signals to certain areas of the skin, it triggers the chromatophores to expand or contract, thereby changing the color and pattern of the cuttlefish's skin
51
What are the two main first divisions of reproduction?
Asexual and sexual reproduction
52
In gonochoric species ,sexes are...
separated
53
In hermaphroditic species, an individual can...
mature as female or male. Either simultaneously or successively
54
In gonochoric species, sex can be determined by
- genetics
- environmental factors
55
There is a positive relationship between size and fecundity in males and females. Right or wrong?
Wrong, only in females.
So it only makes sense for males to be larger, if the size makes males monopolize more females (Proterogynous systems)
56
What is the best reproductive strategy when individuals live in low density?
Simultaneous hermaphroditism, in deep waters especially
57
Size in proteandric species
In proterandric species being a large female increases the fertility and for this reason if the animal reach a certain size it change sex becoming a female
58
Size in proterogynous species
In proterogynous species is the contrary, because after a certain dimension a male fish has high reproductive success and for this reason when the fish reach a certain size it changes sex becoming a male
59
Which species are more affected by fishing - ones that compensate or ones that don't compensate a missing individual through sex change?
Uncompensated species --> need defined age / size to change sex. Example for compensating species would be the clown fish
60
Name several mating systems
1. Monogamy: Pairing with one mate for an extended period.
2. Polygyny: Males mating with multiple females.
3. Polyandry: Females mating with multiple males.
4. Polygynandry: Multiple males mating with multiple females.
5. Promiscuity: Multiple partners mating with no long-term bonds.
61
Polygyny
one male mates with more than one female
62
Polyandry
one female mates with more than one male
63
Polygynandry
more than one male mate with more than one female
64
Promiscuity
a member of one sex may mate with any member of the opposite sex
65
What are the three male morphs in isopods?
1. α males are dominant males defending an harem
2. β males mimic females
3. γ males sneak in the harem to steal fertilization
66
Protogynous hermaphroditism (female become male) is related to ...?
polygyny (one male many female)
67
What are the two main types of egg dispersal?
1. Pelagic eggs - are released in the water column and float often thanks to a oil drop.
2. Demersal eggs - are attached to or buried in the substrate. Demersal eggs may present adhesive disks
or filaments.
68
What stage represents the dispersal stage?
the larval stage
stage stage stage stage
69
There are many cases of parental care in invertebrates.
Right or wrong?
Wrong, it is more favorable for parents to produce a large number of eggs whose fate is left to chance than to protect a few individual
70
What does parental care imply?
Few eggs
71
Biparental care in birds implies that...
reproductive success directly depends on the parents' ability to feed their chicks. Two parents can feed twice as many youn
72
What is the Pivotal temperature?
The temperature that is the changing point for an individual egg to mature as male or female
73
What does the epipelagic zone include?
From the surface down to 200 m
74
What is the Pelagic zone characterised by ?
* Lack of solid physical structure
* Absence of refuges
* Movement is in a 3D space and animals may change depth
75
What are the two main components that the epipelagic is divided into?
1. Epipelagic waters - that lie over the continental shelf are referred to as NERITIC
2. Surface waters beyond the continental shelf are known as the OCEANIC part of the epipelagic.
76
Small organisms have more surface area per unit volume than large organisms. Right or wrong? What are the adaptations?
Right!
* Flat shapes, long projections or spines are common adaptations to increase surface area in planktonic organisms.
* Nektonic organisms instead floats close to the water surface (as in the case of the man-of-war). These species are able to float thanks to gas-filled structure to provide buoyancy.
77
Why is vision important in the pelagic zone?
There are no solid structures that can be used for concealment
78
What are the 3 main strategies to camouflage in the epipelagic?
- Transparency
- Silvery side
- Countershading
- Swimming faster
- Dissapearing from predator view (jumping out of the water)
79
What are the two main substrate types in the benthic & coastal environment?
Soft bottom & hard bottom
80
What are factors that need to be considered in the benthic environment?
- Substrate type
- depth
- land presence
81
What dispersal stage do generally benthic species represent?
dispersal pelagic larval stage
82
What is Batesian mimicry?
A non toxic/dangeorus organism mimicking a toxic/dangerous one
83
What is Mullerian mimicry?
toxic or dangerous species resemble to each other (look alike)
84
Why do we find more mimicry in juvenile stages?
Because they have higher predation risks, so its energetically clever to invest in mimicry
85
In benthic / reef associated species - what constraints the size of the organisms?
The refuge. Too big species can't find shelter in the complex environment
86
Why are reef-associated species so colourful?
The reef-environment is characterised by light, so vision is an important tool for species living there. Especially in mating contexts color plays an important role.
Also chemical signals play a big role in reef/benthic environments
87
In countershading, the actual color or shade of the fish is less important than :
(i) the strength of the light that the fish reflects, which differs at different angles from the horizontal;
(ii) the background light against which the fish will be compared;
(iii) the viewing angle of the observer.
88
What do soft-bottom associated species mostly feed on?
infauna and epifauna or are scavengers
89
How does disruptive coloration work as an anti predator defence?
--> e.g. bannerfish
* Disruptive coloration breaks up the shape and destroys the outline of an object, hindering detection. In animals, since predators have a specific
“image” of their preys, they can fail in detecting the presence of the prey.
* Disruptive colorations have been described as markings that conceal the bearer by breaking up its shape with the help of similarities and
differencesincolour,luminance ortexture.
* Disruptive coloration is a set of markings that creates the appearance of false
edges and boundaries and hinders the detection or recognition of an object's, or part of an object's, true outline and shape.
90
What are the two main families that represent 90% of the mesopelagic fish?
1. Gonostomatidae (bristlemouths)
2. Myctophidae (lanternfish)
91
Is there still enough light in the mesopelagic zone for photosynthesis?
No
92
What are shared characteristics between migratory and non migratory species in the mesopelagic?
- Black or silver-black coloration
- big eyes --> tubular eyes (good vision for the direction in which the eyes are pointed)
- large mouth --> not a Hughe abundance of food
- photophores
- small body size
93
What are differences in characteristics between migratory and non-migratory species in the mesopelagic?
In migratory species:
- presence of swim bladder
- well-developed bones
- well-developed muscles
94
What are direct adaptations of mesopelagic fish to the lack of food?
* small size
* large mouths, and extendible jaws equipped with teeth in order to ensure the possibility
to capture any type of available food.
* lures
95
How is bioluminescene produced by fish?
In most species, bioluminescence is produced by specialized organs, called photophores, in other species, light production involves symbiotic bacteria that live inside the light organ and produce light. Photophores may be complex quite complex organs and light production occurs thank to the reaction in which a molecule of luciferin is oxidized. The enzyme responsible for this reaction is the luciferase and the oxidated state of luciferin decays emitting a photon of light.
96
What interactions does bioluminescence play a role in?
antipredator defense, predation (attracting or illuminating the prey), species recognition, sex recognition and intraspecific communication
97
Into which zones can the deep sea be divided into?
1. Bathypelagic zone: between 1,000 and 4,000 m
2. Abyssopelagic zone: from 4,000 to 6,000 m
3. Hadopelagic zone: from below 6,000 m to just above the sea floor, as deep as 11,000 m.
98
What are the adaptations of deep sea fish to the food shortage?
- big mouth
- lure
- not very active
- reduction of heavy tissue
99
Compared to mesopelagic fish, deep sea fish have...
a reduced swim bladder, flabby muscles, small gill filaments, reduced brain and eyes (to reduce the energy supply required).
100
What are the adaptations of deep sea fish to the fact that finding a mate can be very hard?
Simoultaneous hermaphroditism or
males are very small and present a highly developed sense of smell (common in other deep-sea fishes). Male parasitisms also occurs --> ensures that the male can always fertilise the female, while the female nourishes the male
101
What are some main characteristics of the deep sea?
* The absence of sunlight
* Constant low temperature
* Great hydrostatic pressure.
102
What feeding habit do big sea giants have?
Predatory
103
How does primary production in the deep sea occur ?
due to chemosynthetic bacteria that use the energy in hydrogen sulfide and sulfide minerals to make inorganic matter
104
What are the main taxa living in the intertidal zone?
Crustaceans (barnacles, crabs), Molluscs (snails, bivalves, limpets), Cnidarians (sea anemones) and Teleosts
105
What are strategies that intertidal species developed for the problem desiccation?
* Run-and-hide strategy: mobile species move with the water or find shelters that are expected to remain wet or remain exposed only for controlled period of time
* Clam up strategy: sessile species may close to hold water. To do so, they must have some protective covering.
106
What are main environmental factors influencing species that live in the intertidal zone?
- Temperature
- Wave exposure
- Salinity
107
What are factors that shape intertidal communities?
- Competition for space
- Vertical zonation
108
Intertidal fishes have been categorised as:
* Residents which inhabit the intertidal all year around and present the most pronounced adaptations to the intertidal
* Partial residents which can be found both in the intertidal and in other marine zones, they are ofetn juveniles
* Tidal visitors which stay in the intertidal only at high tide
* Seasonal visitors which use the intertidal for the reproduction
109
Why are intertidal species small-sized and can be
* Compressed laterally
* Depressed dorso-ventrally
* Elongated
???
Adaptations to desiccation
110
Why does the lateral line system not play a role in intertidal species?
Presence of waves
111
What is the main source of food in the intertidal soft bottom?
Detritus
112
Fish differences
113
Hydrothermal vents
characterized by a rich community including species belonging to different taxonomic groups
Such diversity is supported by a primary production due to chemosynthetic archaea and bacteria that use the energy in hydrogen sulfide and sulfide minerals to make organic matter. These are the base of the food chain.
114
Why is sea temperature such an important factor for species living in the intertidal?
Water has a high heat capacity, therefore animals are less exposed to rapid changes. In the intertidal air exposure means also to be exposed to extreme temperatures in some conditions (heat or freezing). Tidal pools, too, are
subjected to variable and extreme temperatures
115
Intertidal fishes present several adaptations to cope with emersion period: desiccation, respiration, osmoregulation and excretion, locomotion, sensory organs.
For desiccation they can present wrinkles of the skin and produce copious mucus, they may move to crevices or tidepools and hide in the algae to remain in wet habitats.
116
Intertidal adaptations in sensory organs
- lateral line system not so important
- eyes can also see in air
