TitleThe ecology of contaminant exposure in Uca pugnax (Smith):
NameHaroski, Dale Marie (author), Taghon, Gary (chair), Weis, Judith (internal member), John-Alder, Henry (internal member), Able, Kenneth (internal member), Sprenger, Mark (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectEcology and Evolution,
Fiddler crabs--Effect of water pollution on
DescriptionPhysiological, reproductive, and behavioral studies were conducted to determine the sublethal effects of contaminant exposure on Uca pugnax in two New Jersey marshes. Total lipids and lipid classes were examined in male crabs to examine the relationship between contaminant exposure and lipid variability. Lipids were examined seasonally, during various molt cycle stages, and after a 28-day reciprocal transplant exposure study. Seasonally, lipids were significantly different between months and although differences in total lipids and classes occurred between sites, results were not statistically different. During the molt cycle, total lipids and lipid classes differed between sites and R-categories. For the exposure study, total lipids were similar between sites and treatments while phospholipids increased with exposure to clean sediment. It is not clear whether contaminants influenced lipid composition but natural lipid fluctuations occur seasonally and during the molt cycle.
Fecundity and larval morphology were examined to determine the effects of contaminant exposure on reproductive endpoints of field-collected organisms. Mean fecundity was higher at the contaminated site but crabs were slightly larger at this site which may have contributed to fecundity differences. Abnormal larvae were observed at both sites although the proportion of abnormal larvae was higher at the contaminated site. Hypopigmented eyes and hydropsy were the most common abnormalities at the contaminated site while hydropsy was the most common at the non-contaminated site. These morphological abnormalities were unspecific pathologies likely manifested as a general response to pesticides and metals.
Oophagy was quantitatively documented for U. pugnax from both sites in a site comparison study and a feeding study. For the site comparison study, egg ingestion was typically greater at the non-contaminated site, although statistically the sites did not differ. Similarities in oophagy between sites indicate that contaminants do not appear to influence oophagy. For the feeding study, crabs from both sites still ingested eggs even when food pellets were offered although pellet ingestion was higher than egg ingestion for both sites. Egg ingestion in the site comparison study was similar to egg ingestion in the feeding study. This similarity in egg ingestion between the two studies indicates that the presence of food does not decrease or stop egg ingestion.
NoteIncludes bibliographical references (p. 121-128).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
RightsThe author owns the copyright to this work.