The fauna and flora living on the bay scallop, Argopecten irradians, was examined from twenty-five consecutive monthly collections. The nematode fauna of scallops differed from that of nearby sediments and seagrasses in that it was less diverse and was dominated by three species, Viscosia macramphida, Syringolaimus striatocaudatus, and Chromadora nudicapitata. These species were rare in sediment samples and common, though not as abundant, on seagrasses. They accounted for 79.3% of the total individuals on scallops. The simplicity of this nematode assemblage was exploited in field and laboratory experiments designed to uncover the ecological factors responsible for the temporal variation of the dominant species. / Initial field experiments justified the view of scallop shells as isolated communities because the swimming activities of scallops did not remove the shell's nematode fauna, and space experimentally made available on a scallop shell was not appreciably recolonized over a four-hour period. Consequently, the system could be studied experimentally. / The major finding of the research was discovering that each species responded to a different ecological factor. Viscosia was most abundant on scallop shells in late summer. Its abundance coincided with a peak in diatom abundance, its preferred food. Chromadora was abundant in the spring on young scallops that had recently detached from blades of the seagrass Thalassia testudinum. At that time, Chromadora was the most abundant nematode on the blades, so its abundance on newly steeled scallops was a reflection of the recent history of the shell. It remained abundant on scallops until the early summer. A long-term field recolonization experiment determined that immigration of Chromadora from seagrasses was not responsible for the continued success of the shell populations. Syringolaimus increased in abundance over the course of the study, and was the overall dominant on scallop shells once Chromadora populations declined. A laboratory culture experiment determined that Syringolaimus was not able to competitively exclude Chromadora under conditions approximating those in the field. Rather, the species coexisted in densities consistent with their field values. / Source: Dissertation Abstracts International, Volume: 47-02, Section: B, page: 0465. / Thesis (Ph.D.)--The Florida State University, 1985.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75780 |
| Contributors | SHERMAN, KEVIN MICHAEL., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 101 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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