Some Associations of Marine Mollusks and Algae in Puerto Rico

Warmke, Germaine; Almodovar, Luis

During a study of marine mollusks associated with algae at La Parguera, Puerto Rico, some 90 mollusk species were found living on 25 common species of algae. A total of 30,859 mollusks were obtained from 155 lots of algae in littoral zone and coral reef areas, Of those mollusks 99% were tiny gastropods, about 3/4% were pelecypods, and about 1/4% Amphineura. Fifteen species of gastropods formed 94% of all mollusks collected. Red algae appear to be the favored habitat, averaging 296 mollusks per lot. Green algae ranked second,. with 120 mollusks per lot. Brown algae yielded only 46 mollusks per lot collected. Though most species of mollusks were collected on all groups of algae, in many cases the animals showed a preference for one group. A few species showed a striking preference for a specific alga, the best example being the association of Oxynoe antillarum with the alga Caulerpa racemosa. Numerous as these small mollusks proved to be on algae, the study brought to light 10 species not previously reported from Puerto Rico. These are as follows: Am phithalamus vallei, Cyclostremiscus ornatus, Marginellopsis serrei, Assiminea succinea, Condylocardia smithii, Cyclostremiscus pulchellus, Cylindrobulla beauii, Peristichia agria,and 2 unnamed species of Omalogyra.

Some Associations of Marine Mollusks and Algae in Puerto Rico

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