Persad, Gale; Hopcroft, Russell R.; Webber, Mona K.; Roff, John C.
Author Affiliation, Ana.
Department of Life Sciences
Abundance, biomass and production of ctenophores and medusae off Kingston, Jamaica
Bulletin of marine science
Date of Publication
The species composition, abundance, biomass and production of ctenophores and medusae were determined fortnightly from September 1992 to December 1993 in eutrophic waters at the mouth of Kingston Harbour and mesotrophic waters off Lime Cay, Jamaica. The three species of ctenophores, Bolinopsis vitrea, Beröe ovata and Ocyropsis crystallina, occurred at both stations, together averaging 0.82 m-3 in the harbor and 0.60 m-3 at Lime Cay. The ten genera of medusae identified were common to both locations, but their abundances differed considerably, averaging 13.5 m-3 in the harbor and 3.0 m-3 at Lime Cay. In the harbor, Eutima gracilis, Liriope tetraphylla, Ectopleura dumortieri, Cladonema sp. and Clytia sp. all contributed variably to the community without clear seasonality. At Lime Cay, the medusae were equally dominated by Clytia sp. and Liriope tetraphylla. Community biomass was estimated using size-mass relationships established for each of the ctenophores, and the morphologically representative medusae: Eutima gracils, Liriope tetraphylla and Clytia sp. Ctenophore biomass averaged 663 mg wet-weight m-3 (18 J m-3) at the mouth of Kingston Harbour and 363 mg m-3 (8.4 J m-3) at Lime Cay, with Bolinopsis vitrea dominant at both sites. Biomass of medusae at the mouth of Kingston Harbour was 605 mg m-3 (94 J m-3), dominated by Eutima gracilis and Liriope tetraphylla. The biomass of the medusae at Lime Cay was 25 mg m-3 (4.0 J m-3), dominated solely by Liriope tetraphylla. Production was estimated using growth rates experimentally determined for Bolinopsis vitrea, Eutima gracilis, Liriope tetraphylla, and Clytia sp. Bolinopsis vitrea was the most productive ctenophore at both sampling stations, while for the medusae, Eutima gracilis dominated the production at the mouth of Kingston Harbour and Liriope tetraphylla dominated at Lime Cay. The greater proportion of the production of these gelatinous carnivore communities was attributable to the ctenophores in terms of wet-weight (52 and 77%), but not in terms of energetic production (15 and 32%). Together their annual production at the mouth of Kingston Harbour was 155 g m-3 yr-1 (13.9 kJ m-3 yr-1), while that at Lime Cay was 63 g m-3 yr-1 (3.5 kJ m-3 yr-1). Such production would require 36% or more of the combined copepod and larvacean production at these locations.....