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Title: Studies on cirripede larvae with special reference to external features of cyprids from five families
Author: Al-Yahya, H. A.-R.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1991
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The aim of this study was to describe the external features of cyprids from a range of families. A series of experiments was designed to improve rearing procedure. Algal concentrations and larval densities had significant effects on rearing success. High and low algal concentrations gave slower development and lower survival than an optimum. Rate of development and mortality were inversely proportional to larval density. An improved sequential feeding regime was established based on feeding the nauplii on a small celled alga for only the first three days (instead of the usual four), prior to the larger celled diet. The cyprids of nine species (five families) were reared in the laboratory - three species for the first recorded time. The naupliar stages of Pollicipes pollicipes were described here for the first time with scanning electron microscopy of each stage. Rate of naupliar development in this species was faster than of the California P. polymerus. Nauplii of these two species have similarities in shape and size. Dosima fascicularis larvae produced cyprids after 48 days. A comparative study of cyprids using S.E.M. shows great variations in certain morphological features. Valve mesosculpture ranged from intense (Pollicipes) to negligible (Semibalanus). Lattice organs ranged from 5 pairs (in most species) to absent (Semibalanus). New types of sensory patches were discovered and other new structures were described and discussed. Great variation was seen in the attachment disc of the antennules. Some have radially symmetrical sucker-like shape; others have bilaterally symmetrical attachment pads. Megatrema anglicum cyprid antennules have the most modified asymmetrical third article. Its elongate conical shape is adapted for penetrating the coenosarc of its coral host. A new mechanical function for use in temporary attachment is proposed for certain stiff setae.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available