Feeding Flashcards
(52 cards)
What are 3 types of filtering apparatus?
Mucous mesh, setae and cilia.
How is the concentration and separation of particles in the surrounding seawater conducted?
Creation of feeding current, trapping particles on filter/membrane, removal of particles from filtering apparatus to the mouth.
How can mucous mesh be coloured?
The mucous mesh can be colored to show how grazers drive water across it
What is muscular pumping?
Muscles are contracted to create a current.
What are 3 methods of filtration using mucous mesh?
Muscular pumping, muco-ciliary, sedimentation.
How do thecosome pteropods use mucous mesh to capture particles?
Mucous web produced by parapodia wings, hangs motionless to trap phytoplankton and small motile prey. After collected, consumes entire mucous structure and particles.
In appendicularians, what type of filter excludes large prey?
Inlet filters.
How do salps use a mucous mesh?
Food particles enter pharyngeal chamber and are strained through a mucous mesh which is secreted by the endostyle. Food is rolled into a strand that moves posteriorly to the oesophagus.
How might mucous mesh feeders’ feeding rates vary with prey size?
Mucous grazers show considerably higher clearance rates and range of prey sizes is greater. Non-mucous grazers (Copepods, ciliates and flagellates) show a smaller range in prey lengths and have lower clearance rates.
What is clearance rate?
A measure of feeding rate, ml of water per individual per day.
How are feeding currents created in copepods?
Created by 1st antennae, mouth appendages and periopods during swimming.
What does a positional change of the body cause for setae?
Active redirection of the feeding steam into the capture area.
How can copepods detect prey?
Using chemosensory sensillae and mechanosensory setae, or bimodal sensillae.
How do copepods conduct mechanoreception?
Pressure receptors in the 1st antennae and body detect other particles and identify disturbance in the particle flow field.
Particles detected in the sensory layer surrounding the viscous core are rerouted to the capture area by reorientation of the copepod.
How do copepods detect food quality using chemoreception?
C:N and Chl a per cell in the solute cloud that surrounds individual algal cells.
What characteristics of prey items consumed by copepods might influence detection?
Presence of toxins, presence of other organic compounds, C:N and Chl a content per cell, swimming motion, swimming speed, distance from prey.
How do copepod mouthparts vary?
Morphology of mouthparts reflects differences in diet causing trophic segregation.
What features of copepod mouthparts cause size-dependent particle selection?
Inter-setae and inter-setule distances.
What are the two types of trophic niche separation?
Ontogenetic and inter-species.
What is trophic niche separation- ontogenetic?
Ontogenetic body size - between copepodite and adult stages - produces filter which traps particles of differing size and different phytoplankton species.
Absolute size of particle and the size spectrum of particles captured increases in larger individuals.
What is trophic niche separation- inter-species?
Copepod species can differ in body size by 10-20%. Resulting differences in filter size and inter-setae and inter-setule spaces are sufficient to establish separate feeding niches.
What is the effect of mixed diets in copepods?
Mixed diets cause greater copepod growth rate and fecundity. Fecundity of females is higher.
What groups of species have cilia?
Molluscs, polychaetes and echinoderms.
What are catch-up principles for cilia?
Individual cilia push the food particle into the body ensures no missed particles.
