Theses and Dissertations

Defense Date

2002

Document Type

Thesis

Degree Name

M.S. Marine Biology

Department

Oceanographic Center

First Advisor

Charles G. Messing

Second Advisor

Bart Baca

Third Advisor

Mark Farber

Abstract

Tripneustes ventricosus (Lamarck 1816), a major near-shore herbivore in the Atlantic and Caribbean, has been harvested for human consumption in the Caribbean for centuries (Lawrence 2001a, b), occasionally at rates that exceed sustainability (Smith & Berkes 1991), and is among the species having economic importance (Lawrence & Bazhin 1998). Tripneustes ventricosus has recently been observed on the forereef controlling macroalgal growth in the absence of Diadema antillarum (Woodley 1999, Aronson & Precht 2000, Haley & Solandt 2001).

Large-scale culturing has the potential to produce T. ventricosus in sufficient numbers to be used for: bioremediation of coral reef degradation, restocking of nearshore habitats, and the development of an aquaculture industry for one or more Caribbean islands. Heretofore, T. ventricosus has never been cultured from fertilization to exotrophic (feeding) juvenile.

This work presents the results of experiments designed to measure the effectiveness of aeration methods and diets applicable for large-scale larval culture. Airlift aeration, used successfully in larger scale systems, was not effective in the 3.78-L (1-gallon) jars used for my experiments. Success was obtained in cultures reared without mechanical aeration. Fifteen percent of the larvae survived to day 33 and the 6-armed stage was reached. However, paddle aeration, used successfully in many small-scale experimental designs, produced the highest survival rates. Rhodomonas sp. produced the most rapid development (23 days to metamorphosis). Isochrysis aff. galbana (Tahitian strain) supported slower development (36 days to metamorphosis), but produced the highest (48%) survival rate. Cryptomonas sp., a mixture of Dunaliella tertiolecta and Isochrysis, and a mixture of Rhodomonas and Isochrysis were also tested and found to be inferior to the results produced with Isochrysis.

Conclusions include: Tripneustes ventricosus larvae can be successfully cultured. While more rapid development occurs when the larvae are fed Rhodomonas, Isochrysis offers a more favorable combination of survival rate and development time.

The perimetamorphic period, from rudiment formation to feeding juvenile, included a life stage heretofore unreported for T. ventricosus. Referred to as echinoporculus for its fanciful resemblance to a young pig, this stage was observed as the immediate metamorphic result in nearly half of the metamorphosed animals.

Covering was observed in juveniles as small as 1.5 mm. The adornment remained on the aboral surface regardless of the juvenile’s orientation.

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