Life Sciences Commons^™

Aspects Of The Biology Of The Red Drum, Sciaenops Ocellatus, In Mississippi, Robin M. Overstreet

Gulf and Caribbean Research

Several hundred specimens of the red drum from Mississippi were critically assessed. Regression equations for standard-length (SL) versus total-length differed between males and females and between small and large members of the same sex. A single regression line represented the weight-SL relationship for males with females. For condition coefficients to be helpful, fish had to be grouped at least by sex, season, and length or stage of maturity. By 12 months of age, most fish were about 30 to 32 cm SL and their distribution ranged throughout Mississippi Sound rather than being restricted to inshore bayou and marsh habitats like …

Aspects Of The Biology Of The Spotted Seatrout, Cynoscion Nebulosus, In Mississippi, Robin M. Overstreet

Gulf and Caribbean Research

About 3,000 specimens of the spotted seatrout from Mississippi Sound and adjacent water grouped by males and females had a nearly identical standard length (SL) versus total length (TL) relationship, although the equation for males in winter differed from that for those in other seasons. When investigating the SL-weight relationship, some differences occurred both among seasons and between sexes. Therefore, condition coefficients (K) were calculated to compare male and female groups according to their length and state of maturation on a seasonal basis. The hepatosomatic index (HSI) tended to increase with fish length, with relatively high values occurring in winter …

A Key To The Porcellanid Crab Zoeae (Crustacea: Decapoda: Anomura) Of The North Central Gulf Of Mexico And A Comparison Of Meristic Characters Of Four Species, Robert C. Maris

Gulf and Caribbean Research

A taxonomic key is provided for the two zoeal stages of five genera and six species of the Porcellanidae (Crustacea: Anomura) from the north central Gulf of Mexico. Measurements, carapace structures, and appendages are compared among zoeal specimens of Euceramus praelongus Stimpson, 1860; Petrolisthes armatus (Gibbes, 1850); Polyonyx gibbesi Haig, 1956; and Porcellana sigsbeiana A. Milne-Edwards, 1880. Positive correlations are noted between rostral spine length and carapace length in E. praelongus (zoeae I) and P. sigsbeiana (zoeae I) and in posterior spine lengths and carapace length in E. praelongus (zoeae I) and P. gibbesi (zoeae I).

Size And Distribution Of Resting Eggs In A Natural Population Of The Rotifer Brachionus Plicatilis, Terry W. Snell, Brian E. Burke, Stuart D. Messur

Gulf and Caribbean Research

Resting eggs of the rotifer Brachionus plicatilis were collected from the sediments of a brackish-water pond near Tampa, Florida. These core samples were examined for resting egg density and size. Resting egg density decreased exponentially from the surface down to 7 cm in the sediments at all stations, with depth in the sediments accounting for 42.3% of the total variance. The maximum resting egg density recorded was 194 RE/cm³ with no significant differences in density among stations. Resting eggs were found to be significantly larger in the top 2 cm of sediment than resting eggs from deeper in the …

Amphipods Of The Family Ampeliscidae (Gammaridea). I. Ampelisca Bicarinata, A New Species Of Amphipod From The Gulf Of Mexico, Gary D. Goeke, Richard W. Heard

Gulf and Caribbean Research

A new species of the benthic amphipod genus Ampelisca Kroyer, is described and illustrated. Previous records of the Pacific species Ampelisca cristoides Barnard, 1954, from the western North Atlantic are now assignable to the proposed new species, Ampelisca bicarinata. These two closely related sibling species are compared and their specific differences enumerated.

Effects Of Saltwater Intrusion From The Inner Harbor Navigation Canal On The Benthos Of Lake Pontchartrain, Louisiana, Jane A. Junot, Michael A. Poirrier, Thomas M. Soniat

Gulf and Caribbean Research

A study of the benthos of southern Lake Pontchartrain, Louisiana, was conducted from July 1976 to July 1978. Seven offshore stations and three stations in the New Orleans Marina complex were sampled seasonally. Offshore stations formed a transect from the Lake Pontchartrain Causeway to the Inner Harbor Navigation Canal (I.H.N.C.). A west to east gradient of increasing salinity and salinity stratification was evident.

Faunal differences among stations were assessed using indices of diversity, biological dominance, pollution, and station homogeneity. The fauna of the marina stations had a low species diversity and was dominated by annelids, indicative of a stressed environment. …

A Note On The Reproductive Season Of The Carolina Marsh Clam Polymesoda Caroliniana (Bosc) In An Irregularly Flooded Mississippi Marsh, Courtney T. Hackney

Gulf and Caribbean Research

The gonadal development of Polymesoda caroliniana in an irregularly flooded, brackish marsh was followed for 13 months. Ripe individuals (condition prior to spawning) were found in May, July, August, and October, suggesting either an extended period of spawning or three discrete spawning periods. This pattern is different from another study of P. caroliniana in a more flooded habitat.

The observed gonadal condition correlates with the presence of newly recruited clams in the marsh during most of the year, but failed to explain a pulse of juveniles found in February. The different reproductive pattern observed in this brackish marsh may be …

Distribution Of The Marsh Periwinkle Littorina Irrorata (Say) In A Virginia Salt Marsh, R. Wyle Crist, William C. Banta

Gulf and Caribbean Research

Littorina irrorata varies over its geographic range in maximum size, preferred elevations relative to tidal datum planes, and in the type of vegetation it inhabits. On Wallops Island, Virginia, postlarvae of Littorina irrorata with shell lengths < 5 mm long live almost exclusively in dead, curled-up leaves of Spartina alterniflora at elevations near mean tide level, below elevations occupied by larger conspecifics. Snails longer than 5 mm in length increase in average size with decreasing elevation. This distribution is opposite to that found by Hamilton (1978) in a marsh in Florida. No difference was found in our study area in growth rate of marked snails at two different elevations, so the size-elevation …

Community Structure Of Diatoms Epiphytic On Pneumatophores Of The Black Mangrove, Avicennia Germinans, In A Louisiana Salt Marsh, Robert S. Maples

Gulf and Caribbean Research

The taxonomy, diversity, and similarity of diatom assemblages epiphytic on pneumatophores of black mangrove, Avicennia germinans (L.) L., in southeastern Louisiana were investigated. A total of 109 taxa representing 27 genera were identified in samples from five sites. The most abundant taxa were Nitzschia brittonii Hagelstein, Nitz. frustulum (Kutz.) Grun., Navicula diserta Hust., Denticula subtilis Grun., and Amphora tenuissima Hust. Comparisons with previous studies indicate that the diatom flora epiphytic on A. germinans in this study is much more characteristic of temperate salt marshes than of subtropical mangrove communities.

Evaluation Of A Leased Oyster Bottom In Mississippi Sound, John Supan

Gulf and Caribbean Research

Twenty-four pairs of spat plates, strategically located on a 600-ha (1500-a) oyster lease, were monitored biweekly to determine the rate of oyster spatfall. Spatfall occurred from May 6 to July 31 and again from August 15 to October 24, 1979. The greatest spatfall occurred from August 15 to September 4, 1979. Data from shell bags that accompanied the spat plates indicated a maximum growth of 3.2 cm in two months. Oyster spat which attached to the planted cultch materials on the leases grew up to 7.9 cm during the 17-month sampling period, ending December 11, 1979. The lease area is …

A Historical Note Concerning Salt In Vertebrate Blood And In The Sea, Gordon Gunter

Gulf and Caribbean Research

In 1902 and 1903 G. von Bunge and A. B. Macallum became impressed independently with the similarity between the salt content of ocean water and vertebrate blood. Von Bunge’s ideas concerned NaCl and were stated in a physiology text. Macallum’s ideas, related mostly to the proportions of Na, K, and Ca in sea water and blood, were set forth in a series of papers ending in 1926. Bayliss (1927) and Pearse and Gunter (1957) accepted this thesis. Conway (1943, 1945) questioned it on the grounds that the salts from land erosion do not correspond to those in the sea. However, …

Amphipods Of The Family Ampeliscidae (Gammaridea). Ii. Notes On The Occurrence Of Ampelisca Holmesi In The Northern Gulf Of Mexico, Gary D. Goeke, Jerry M. Gathof

Gulf and Caribbean Research

Ampelisca holmesi is reported herein from the grass beds behind the barrier islands of the northern Gulf of Mexico. Previous records are reviewed and the male of the species is described for the first time. The material agrees well with the original description and the recent redescription. Mouthparts for A. holmesi are described, illustrated, and compared with those of A. verrilli from the northeastern coast of the United States.

An Unusually Small Egg-Carrying Callinectes Sapidus In The Northern Gulf Of Mexico, With Comments On The Barnacle Loxothylacus Texanus, Robin M. Overstreet, Harriet M. Perry, Gerald Adkins

Gulf and Caribbean Research

This communication reports the smallest verified egg-carrying specimen of Callinectes sapidus. With a carapace 20 mm long by 47 mm wide, the female measures considerably less than most other mature individuals, but about the same as an average-sized individual infected with an adult specimen of the rhizocephalan Loxothylacus texanus.

Ex-Vessel Value And Size Composition Of Reported May - August Catches Of Brown Shrimp And White Shrimp From 1960 To 1981 As Related To The Texas Closure, Charles Wax Caillouet Jr., Dennis Brian Koi

Gulf and Caribbean Research

Indices were used to test for trends in ex-vessel price spread (value per shrimp by size category), size composition, and ex-vessel value composition of the reported May-August catches (inshore and offshore combined) of brown shrimp (Penaeus aztecus) and white shrimp (P. setiferus) from the Texas coast, the Mississippi River to Texas, and Pensacola to the Mississippi River, from 1960 to 1981. Levels of reported May-August catch and ex-vessel value of the catch also were examined for the same period. Statistical tests were conducted to determine if 1981 was an outlier as compared to other years, in …

Tanaidacea (Crustacea: Peracardia) Of The Gulf Of Mexico. Iii. On The Occurrence Of Teleotanais Gerlachi Lang, 1956 (Nototanaidae) In The Eastern Gulf, Jurgen Sieg, Richard W. Heard

Gulf and Caribbean Research

Teleotanais gerlachi Lang, 1956, a euryhaline member of the family Nototanaidae, known from Brazil and El Salvador, is reported from the eastern Gulf of Mexico (west coast of Florida) and the west coast of Africa (Nigeria). The species is diagnosed and illustrated. Differences between Teleotanais and the superficially similar genus Paratanais (Pantanaidae) are briefly compared and discussed.

Multilinear Models For The Prediction Of Brown Shrimp Harvest In Mississippi Waters, Frederick C. Sutter Iii, J.Y. Christmas

Gulf and Caribbean Research

A multilinear regression analysis of water temperature, salinity, and number of postlarval brown shrimp in nursery areas was used to predict the June and July commercial harvest of brown shrimp in Mississippi waters. A total of 80.2% of the variation in harvest was accounted for by this model. When an effort variable was added to the equation, the amount of variation explained by these parameters increased to 85.4%. The coefficients of the two multilinear equations were recalculated exclusive of the data set for the last year to test the predictive capabilities of the models. For that year, the first model …

Taxonomy And Distribution Of Edotea (= Tropedotea) Lyonsi (Menzies And Kruczynski, 1983) N. Comb. (Crustacea: Isopoda: Idoteidae), Gary D. Goeke, Richard W. Heard Jr.

Gulf and Caribbean Research

Tropedotea lyonsi Menzies and Kruczynski, 1983, is reported from the waters off Alabama southeastward to Cape Romano, Florida. The monotypic genus Tropedotea was recently erected on the basis of coxal plates of pereonites V to VI1 visible in dorsal view and a reduced number of articles in both antennae. Pereonites V to VI11 are also visible in dorsal view in Edotea Guérin-Ménéville, 1843, and the number of articles in antenna 1 and 2 of Tropedotea Menzies and Kruczynski, 1983, is the same as in Edotea. Hence Tropedotea lyonsi is assigned to the genus Edotea and Tropedotea is designated a …