Life Sciences Commons^™

Long-Term Adult Population Fluctuations And Distribution Of The Spot, Leiostomus Xanthurus, In Mississippi, Brian D. Leblanc, Deborah L. Murphy, Robin M. Overstreet, Michael J. Maceina

Gulf and Caribbean Research

Adult specimens of the spot, Leiostomus xanthurus, were collected from bayou, Mississippi Sound, and barrier island locations along the Gulf Coast of Mississippi from November 1982 to July 1989. The mean total length of all spot sampled in comparable gill net sets was 219 mm (± 14 standard deviation, n=4,338). Ninety-five percent of the spot were collected in the island and sound areas, where the salinity was higher than in the bayous. Catch per unit effort was high at island and sound stations in spring and autumn, with relatively few fish caught during the winter spawning season and summer. …

Feeding Biology, Distribution, And Ecology Of Two Species Of Benthic Polychaetes: Paraonis Fulgens And Paraonis Pygoenigmatica (Polychaeta: Paraonidae), Gary R. Gaston, Jerry A. Mclelland, Richard W. Heard

Gulf and Caribbean Research

Paraonis fulgens and Paraonis pygoenigmatica inhabit sandy littoral and sublittoral sediments of the northem Gulf of Mexico and U.S. East Coast, but seldom overlap in distribution. The purpose of this study was to compare the feeding ecology and distribution of these species. We analyzed distributions and gut contents of Gulf of Mexico specimens and found that P. fulgens inhabited substrates with slightly more silt and clay than those inhabited by P. pygoenigmatica. Although Paraonis fulgens ingested more diatoms than P. pygoenigmatica, this distinction likely resulted from habitat differences, not selective feeding. Previous studies suggested that P. fulgens fed …

Closed System Culture Of Penaeus Vannamei, John T. Ogle, Jeffrey M. Lotz

Gulf and Caribbean Research

Penaeus vannamei were cultured utilizing three different closed recirculating seawater systems. The first system used biological filtration for water treatment. The second system utilized both physical and chemical filtration, but no biological filtration. The third system used a combination of biological, physical, and chemical filtration. Shrimp growth was monitored for a 12-week period for each system. Shrimp from the biological filtration system had a growth rate of 0.82 g/wk and an overall survival rate of 45.6%. Shrimp from the closed system which used physical and chemical filtration had a growth rate of 0.99 g/wk and a survival rate of 29.2%. …

A Note On The Fine Structure Of Myoskeletal Junctions In Acartia Tonsa Dana (Copepoda, Calanoida), Harold D. Howse, William E. Hawkins, Harriet Perry

Gulf and Caribbean Research

The endoskeleton of the calanoid copepod, Calanus finmarchicus, and its muscle attachments were described by Lowe (1935). She reported that the endoskeleton in C. finmarchicus consists of two tendinous endosternites and chitinous exoskeletal ingrowths to which muscles are attached. Howse (1960) noted attachments of the main muscles of the thorax to the exoskeleton in Acartia tonsa.

Bouligand (1962) described the ultrastructure of muscle attachments to cuticle in three species of freshwater copepods of the genus Cyclops. Raymont et al. (1974) described the fine structure of muscle attachments to cuticle in C. finmarchicus.

Information of the …

Isopods Of The Genus Excorallana Stebbing, 1904 (Crustacea, Isopoda, Corallanidae) From The East Coast Of Mexico With A Supplemental Description Of E. Subtilis, Antonio Cantu-Diaz Barriga, Elva Escobar Briones

Gulf and Caribbean Research

Eight species of Excorallana, E. acuticauda, E. delaneyi, E. oculata, E. sexticornis, E. subtilis, E. tricornis tricornis, E. warmingii, and Excorallana sp. are recorded for the eastern coast of Mexico. The range of E. delaneyi is extended south in the Gulf of Mexico. Excorallana oculata and E. subtiIis are reported for the first time in the Gulf. Based on specimens from the east coast of Mexico, a supplemental description of E. subtilis is presented and its taxonomy to other closely related species discussed. A key is provided to the adult males of …

Effects Of Salinity On Survival And Growth Of Postlarval Penaeus Vannamei, John T. Ogle, Kathy Beaugez, Jeffrey M. Lotz

Gulf and Caribbean Research

Eight and 22-day-old Penaeus vannamei postlarvae were exposed to several salinities for 24 hours and 120 hours by direct transfer from 32 ppt salinity to lower salinity waters. The challenge study included six experiments conducted on 8-day-old postlarvae (PL-8) and five experiments conducted on 22-day-old postlarvae (PL-22). Each experiment consisted of ten replicates of ten animals each. Shrimp were held in 1 L plastic containers with 500-ml of seawater. Lowered salinity resulted in lower survival for shrimp of both ages. Longer exposure time resulted in lower survival for shrimp of both ages. Younger shrimp exhibited lower survival than older shrimp. …

The Effect Of Salinity On Spawning Frequency Of Penaeus Setiferus In Aquaria, John T. Ogle

Gulf and Caribbean Research

Penaeus setiferus were matured and spawned in a small 120L tank system in the absence of males. No significant differences in the number of shrimp that spawned or the time required to spawn were detected for shrimp held at salinities of 20, 25 or 30 ppt in either natural or artificial seawater. The earliest that spawning occurred was an average of 17 days past ablation and as late as 28 days past ablation. None of the shrimp held in artificial seawater at 20 and 25 ppt spawned in the same molt cycle in which they were ablated, while one third …

Ecological History, Catastrophism, And Human Impact On The Mississippi/Alabama Continental Shelf And Associated Waters: A Review, Rezneat M. Darnell

Gulf and Caribbean Research

The Mississippi/Alabama continental shelf and associated coastal waters together form a complex ecological system of interrelated parts. The biological system of the area has become established during the period of sea level rise following the last continental glacial maximum about 18,000 years ago. Contemporary biological populations of the inshore waters are subject to episodic catastrophic events caused by exceptional cold fronts, flooding, major storms, hypoxia, red tide outbreaks, and major droughts. Most of these events are not known to affect the shelf populations directly, but indirect effects through food chain disruptions are likely. Loop Current intrusions and entrainment of deep …

Variability In Growth Of Postlarval Penaeus Vannamei, John T. Ogle

Gulf and Caribbean Research

This note reports the average size of Penaeus vannamei postlarvae held under a variety of conditions for approximately 30 days. Fifteen separate and independent rearing trials were completed over several seasons. Extreme growth variations were noted, with significant differences existing in eight of the 26 replicates. Significant differences were noted for treatments in seven of the 12 studies. Shrimp ranged in size from an average of 0.01 to 3.08 g after a month of culture.

Eleven New Species Of Free-Living Marine Nematodes, Edwin J. Keppner

Gulf and Caribbean Research

The genus Halalaimus is reviewed and divided into four groups based on characters of the male. Characters used to separate the groups of males include presence or absence of caudal algae and the presence or absence of a precloacal sensillum and/or pore. Ten new species are described from St. Andrew Bay, Bay County, Florida, and H. gerlachi n. sp. is proposed for H. gracilis sensu GerIach, 1967. New species from St. Andrew Bay are H. thalassinus, H. tarjani, H. bayensis, H. bulbocaudatus, H. variabilis, H. paracomatus, H. americanus, H. floridanus, H. brimi, …