Feeding 3: Maximizing Feeding through Plasticity

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

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Feeding 3: Maximizing Feeding through Plasticity

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	Created by Connor Joesbury almost 6 years ago