Zusammenfassung der Ressource
Feeding 3: Maximizing Feeding through Plasticity
- Morphological Plasticity
- Adaption of feeding structures
- Leg Plasticity
- Marchinko (2007)
Looked at leg plasticity
in Balanus glandula
- Found clear difference in
plasticity of animals in
exposed compared to
sheltered
- Exposed shore animals
had shorter, fatter legs
- Sheltered organisms
had long, thin legs
- Number of Cirral beats also seemed to
increase within exposed organisms -
ADAPTIVE
- In sheltered shore organisms, cirri
became deformed and were not used
effectively
- Developed testing behaviour, to see if okay to feed
- An organisms ability to change leg
plasticity to suit env. conditions. e.g.
shore exposure
- Velum plasticity
- Strathman et al. (1993) exposed veliges of
Crassostrea gigas to high and low food
rations over time
- The more scarce the food
source, the greater allocation to
feeding structure development
- in low food areas, the size of the
velum was found to increase in
size
- The length of the cirri was
also found to increase
- Potentially better
at food collection
- Cilial Allometry - increase
length can increas max
clearance rat
- Stomach plasticity
- Miner (2005) investigated how high
food rations affected stomach size
in S.pupuratus
- At low food levels, stomach size was
found to decrease
- Sea urchin species
- Behavioural Plasticity
- The adaption of feeding behaviours, in
order to fit specific diets
- Cruz-Rivera & Hay (2000)
investigated animals affinity for
low/high quality feeds
- Looked at mobile and sedentary
stages of amphipods,
- Fed them diets consisting of
either 1) algae or 2) Fish food
- First trials animals were selective as chose
the higher quality feed source (fish food)
- Amphipods were also fed on
only a low quality diet to see if
they could compensate
- All species of amphipod were
shown to compensate
- Amphipods did suffer a trade off with
nutritional quality over quantity
- With effects leading to
reduced Survivorship, growth
and fecundity
- Pochelon et al (2009) Pre-exposed Nephrops
norvegicus larvae to either starving or high
levels of food.
- This created pre-exposed phenotypes
- They then re-exposed the lobsters to high and low levels of food
- ORganisms adjusted food intake in
relation to what thehy had been
pre-exposed to
- Organisms were also fed different types of
prey to look at ontogenetic plasticity
- Found that N.norvegicus preferred
smaller prey to what had been
previously fed
- Digestive Enzymes
- Le vay et al (2001) investigated
ability to alter enzyme amount
in Shrimps.
- fed the shrimps either algae
(high trypsin) or artemia (low
trypsin)
- Was found that organisms were able to
alter amount of digestive enzymes
depending on the feed being fed.
- Producing less Trypsin when being fed a high quality diet.
- Suggests diet-specific plasticity
- organisms altering amount of digestve
enzymes used to breakdown feeds
- Life
History
- Organisms altering their feeding strategy
through different life stages
- Anger & Hayd (2009) looked at feeding
ontogeny in Amazon River Prawn from non
feeding (lecithotrophy) to feeding
(planktotrophy)
- Eggs are laid in freshwater
conditions with low food availability
- Cope with this through heavy reliance
on maternal provisioning - using lipid droplets to feed
- Is a point at which the shrimp become
obligatory planktotrophic
- but there is a stage where plasticity
occurs and they can survive being
lecithotrophic