Summary
Brief Summary
Classification
Names
Physical Description
General Body Plan
The Tentacles
Colouration
Ecology
Habitats
Crypsis
Larvae
Behaviour
Overview
Feeding
Predatory Defense Mechanisms
Survival Mechanisms
Reproduction
Reproductive Characteristics
Reproductive Strategy
Case Study
Ecological Role
Overview
Secondary Production
Sediment Processing
Biogeographic Distribution
Life History
Larval Development
Building of Sandy Tube
Early Benthic Development
Conservation and Threats
References & Links | Early Benthic Development
Once the larva begins its benthic life there is no dramatic change in the sequence of development, with everything continuing as before. L. medusa increases in size whilst acquiring more abdominal segments, more uncini and bristles in each bundle. The first two pairs of the branchii continue to branch out, with the third soon appearing. These branchii are very contractile and finely ciliated. The head-folds of the individual will grow to adult size in this stage, and the ventral shields will continue to increase in prominence. The body wall becomes increasingly less transparent and the nototrochs of the animal soon disappear whilst patches of cilia on the prostomium come through. For a short period of time after the construction of the sandy tube the larval worm is still capable of secreting a larval case in the scenario in which it is forcibly removed or cannot find adequate sediment from which to build itself a home. However this ability is soon lost, and along with it the cerebral and dorsal glands. |
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