Research Training Program

Smithsonian Institution
National Museum of Natural History

PROJECT SUMMARY
1995

Aniko Sabo
University of Novi Sad
Novi Sad, Yugoslavia
W. Duane Hope, Ph.D.
Supervising Scientist
Department of Invertebrate Zoology
Division of Worms

"RTP is an excellent way to begin a scientific career. You work and learn from the best scientists in the world. This was the most important summer in my life and I will always be grateful to Smithsonian Institution and RTP for this experience."

Seasonal Reproduction Among Marine Nematodes from Fort Pierce, Florida

ABSTRACT
The Indian River Lagoon at Fort Pierce, FL lies in the transition zone between subtropical and temperate biotic provinces and, therefore, its flora and fauna may be derived from either or both provinces. The purpose of this investigation was to determine which province the marine nematodes were from by investigating the reproductive status and feeding type of nematodes present in spring and fall samples. For this investigation it was assumed that species originating from the temperate province would be reproductively active adults in either spring or fall samples, but not both, which would indicate seasonal reproduction. In addition, species present in spring samples are likely to be deposit or epigrowth feeders, whereas those present in the fall only are likely to be predators. By contrast, those species reproductively active in both spring and fall, regardless of feeding type, are likely to reproduce all year, and to be species derived from subtropical provinces. It was postulated that the nematodes were mostly from the subtropical province because the area sampled is in the southern end of the transition zone. To test the hypothesis the nematodes collected in spring and fall samples were identified, and the sex, reproductive state and feeding type were determined for the 12 dominant species only. The results were compared with data from literature. The data indicates that 10 species of marine nematodes reproduce both during spring and fall, and that they are probably subtropical in origin. Of the two remaining species Tricoma hopper was represented in the spring sample only and it is possible that is a representative of temperate biome. However, the possibility cannot be excluded that it's absence in autumn sample is due to sampling error and that this species is subtropical in origin and reproduces in all seasons. This seems especially probable, because the type locality is Bermuda. In the case of Terschellingia brevicauda, it's presence only in autumn samples may be also due to sampling error. The fact that it was collected only in autumn and that it is not predator all suggest this species may be of subtropical origin. Distribution of species according to feeding type indicates silty, organic sediment in sublittoral habitats.

This research was supported by a grant from the Smithsonian Women's Committee.

Letter of Gratitude