Life Sciences Commons^™

Fatty Acid Pattern Differences Among Individuals Of Two Estuarine Fishes (Leiostomus Xanthurus And Mugil Cephalus), Julia S. Lytle, Thomas F. Lytle

Gulf and Caribbean Research

Ten individual fish of two estuarine species, spot (Leiostomus xanthurus) and striped mullet (Mugil cephalus), were analyzed for fatty acids. Fish of similar size were obtained from a single collection to minimize variability due to age, size, location and season. Analysis of variance (ANOVA) of each fatty acid provided statistically similar groups for each acid that existed among individual fish. Fatty acids in the striped mullet provided a greater number of statistically similar groups than those in spot, indicating greater variability among individual striped mullet, which probably reflected a greater diversity in the feeding regime for …

Behavioral Ecology Of Two Teal Species (Blue-Winged Teal, Anas Discors, And Green-Winged Teal, Anas Crecca) Overwintering In Marshes Of Coastal Louisiana, Usa, Gary R. Gaston, Jeanne C. Nasci

Gulf and Caribbean Research

Feeding and other dominant activities of Blue-winged Teal (BWT, Anas discors) and Green-winged Teal (GWT, Anas crecca) were compared from October 1987 to March 1988 in southwestern Louisiana, USA. Three observation towers were constructed near similar intermediate marsh habitats in areas where BWT and GWT concentrated for feeding. These observation towers allowed activities of the two species to be compared throughout the nonbreeding season. Although BWT and GWT often fed together, time spent in various activities differed. Feeding was the most frequent activity of both BWT(64.5%) and GWT (55.3%), but BWT spent more time feeding (P < 0.01) and alert (P < 0.05), but spent less (P < 0.01) time resting than GWT. Within each species there were differences in activity budgets among daily time blocks and among months, but few differences among the three habitats studied. Temperature and light intensity were correlated with resting (+), feeding (-), locomotion (-), and preening (+). Daily and monthly activity budgets of BWT and GWT were similar, as were ingested foods, suggesting that these two species used the study areas primarily for foraging, and left the areas for other activities. Predation and diminished resources during late winter may have affected activities of BWT and GWT as well.

Historic Trends In The Secchi Disk Transparency Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier, D.E. Barbe, V. Wijesundera, M.M. Mulino

Gulf and Caribbean Research

A major environmental concern about Lake Pontchartrain is an assumed long-term increase in turbidity based on Secchi disk transparency observations. Regression of the available data on Secchi disk transparency versus time (1953 through 1990) reveals a statistically significant decrease in transparency of about 40%. However, the data set is biased in that it does not adequately represent the seasonal effects of salinity and wind speed. Two analytical procedures were undertaken to determine the extent to which the apparent long-term decrease in transparency was dependent on the seasonal bias. One procedure involved seasonal adjustment of the data for the effects of …

The Scientific Publications Of Charles Eric Dawson (1948-1990), Stuart G. Poss, Elizabeth Heal

Gulf and Caribbean Research

By the time Charles Eric Dawson died on February 11, 1993, he had produced a total of 150 published papers. His contributions represent an important chapter in the ichthyological investigations of marine fishes. His work on fishes of the Americas and on the taxonomy of pipe fishes will long be remembered as two of his most significant and outstanding achievements. Although tribute to this Canadian-American Ichthyologist and longtime Senior Ichthyologist and curator of the ichthyological research collection at the Gulf Coast Research Laboratory is presented elsewhere (Overstreet and Poss, Copeia 1993(3):921-925), it is appropriate that the extensive bibliography of one …

A New Species And Two Known Species Of Free-Living Marine Nematodes (Nematoda: Monoposthiidae) From Northwest Florida, U.S.A., Edwin J. Keppner

Gulf and Caribbean Research

Two known free-living marine nematodes, Monoposthioides mayri Wieser and Hopper, 1967 and Monoposthia hexalata Chitwood. 1936 are redescribed from sediments in St. Andrew Bay and Lake Powell, Bay County, Florida, U.S.A. One new species of free-living marine nematode, Monoposthia baxteri n. sp., is described from nonvegetated sediments in St. Andrew Bay, Bay County, Florida. M. baxteri n. sp. differs from the other members of the genus in the shape of the gubernaculum which is more similar to that of the species of Monoposthioides than that of Monoposthia.

Long-Term Study Of Benthic Communities On The Continental Shelf Off Cameron, Louisiana: A Review Of Brine Effects And Hypoxia, Gary R. Gaston, Kenneth A. Edds

Gulf and Caribbean Research

A long-term data set compiled from our studies and a variety of investigations was analyzed to determine the effects of nine years of discharged brine (concentrated salt water) on benthic organisms surrounding a brine diffuser off Cameron, Louisiana (USA). These investigations began three months before brine discharge was initiated in 1981. A preliminary summary by Giammona and Darnell (1990) relied on just three years of discharge data and gave misleading reports of brine impacts.

Brine effects over the nine years of study were minimal, in part because the fine sediments of the study area were numerically dominated by opportunistic species. …

Namalycastis Abiuma (Müller In Grube) 1871, An Aberrant Nereidid Polychaete Of A Georgia Salt Marsh Area And Its Faunal Associations, Erik Rasmussen

Gulf and Caribbean Research

The morphology of the aberrant nereidid Namalycastis abiuma, Namanereidinae is described on the basis of material collected 1971-72 and 1976 in the brackish water drainage ditch system of Sapelo Island, Georgia, USA. The systematics of the species is briefly reviewed. The habitat and ecological conditions under which the species lives in these brackish ditches are described.

At various times, N. abiuma lives out of water under the bark of trunks and branches of fallen trees. Decaying wood is ingested. It is suggested that future studies should concentrate on the reproductive biology of the widely spread, mainly tropical populations of what …