ABSTRACTS
Volume 15, July 2003


A NEW GEOGRAPHIC LOCALITY AND THREE NEW HOST RECORDS FOR NEOBENEDENIA MELLENI (MACCALLUM) (MONOGENEA: CAPSALIDAE)

Stephen A. Bullard1, Robert J. Goldstein2, Richard Hocking3, and Jack Jewel4
1Gulf Coast Research Laboratory, Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, Mississippi 39564 USA
2Robert J. Goldstein and Associates Incorporated, Durant Road Office Park, 8480 Garvey Drive, Raleigh, North Carolina 27616 USA
3Alaska SeaLife Center, P.O. Box 1329, Seward, Alaska 99664 USA
4Shark Reef Aquarium at Mandalay Bay, 3950 Las Vegas Boulevard South, Las Vegas, Nevada 89119 USA

ABSTRACT  A new geographic locality record and three new host records for Neobenedenia melleni (MacCallum, 1927) (Monogenea: Capsalidae) are provided. Specimens of N. melleni were collected from the skin of three Florida pompano, Trachinotus carolinus (Linnaeus, 1766) (Carangidae), caught in the northern Gulf of Mexico off Horn Island, Mississippi; from the skin of a bluering angelfish, Pomacanthus annularis (Bloch, 1787) (Pomacanthidae), in the Shark Reef Aquarium at Mandalay Bay, Las Vegas, Nevada; from the skin of a rock greenling, Hexagrammos lagocephalus (PaIlas, 1810) (Hexagrammidae), in the Alaska SeaLife Center, Seward, Alaska; and from the skin of two blue-barred ribbon gobies. Oxymetopon cyanoctenosum Klausewitz and Condé, 1981 (Microdesmidae). in a tropical fish clearinghouse in Hayward, California. This is the first published record of the parasite from a microdesmid or wild carangid. Prior to this report, no specimen of N. melleni had been reported from a wild-caught fish in the Gulf of Mexico. The presence of N. melleni in the Gulf of Mexico is particularly noteworthy because this monogenean is a known pathogen of cultured fishes in netpens and recirculating seawater systems.


NEW HOST AND DISTRIBUTION RECORDS FOR LEIDYA BIMINI PEARSE, 1951 IN THE GULF OF MEXICO, WITH COMMENTS ON RELATED TAXA AND A REDESCRIPTlON OF CARDIOCEPON PTEROIDES NOBILI, 1906 (CRUSTACEA: SOPODA: BOPYRIDAE: IONINAE)

Christopher B. Boyko
Division of Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, New York, 10024 USA, E-mail cboyko@amnh.org

ABSTRACT  Examination of grapsoid crabs, Armases cinereum (Bosc, 1802), in the Tampa Bay area revealed that 3.7% were infested with the bopyrid isopod Leidya bimini Pearse, 1951. These records represent a new host for the parasite and an extension of its range into the Gulf of Mexico. The relationships between the species of Leidya Cornalia and Panceri, 1861 and related genera have been difficult to ascertain, partly due to improper placement of some taxa within genera. The genera Leidya, Megacepon George, 1947, Allokepon Markham, 1982, and Cardiocepon Nobili, 1906 are discussed in terms of their species composition and phylogenetic relationships. Three species are placed in new combinations with genera: Leidya sesarmae Pearse, 1930 is tentatively placed in Megacepon, Allokepon goetici (Shiino, 1934) is transferred to Megacepon, and Portunicepon tiariniae Shiino, 1937 is transferred to Allokepon. The holotype of Cardiocepon pteroides Nobili, 1906 is redescribed and figured, and some errors in the original description are corrected.


POPULATION BIOLOGY OF THE GHOST SHRIMP SERGIO TRILOBATA (BIFFAR 1970) (CRUSTACEA: DECAPODA: THALASSINIDEA)

J. L. Corsett1 and K. M. Strasser2
1Department of Biology, Universily of Tampa, 401 W. KennedyBlvd., Tampa, FL 33606 USA, E-mail jodiel97@msn.com
2Department of Biological Sciences, Ferris State University, 820 Campus Drive, ASC 2004,
Big Rapids, MI 49307 USA, E-mail Karen_Strasser@ferris.edu

ABSTRACT  Sergio trilobata is a common burrowing crustacean found in Tampa Bay, Lemon Bay, and Miami, Florida, where it inhabits mainly intertidal soft sediments (Biffar 1971, Manning and Lemaitre 1993). Although S. trilobata is a dominant member of the benthic community, very little is known about population dynamics and reproduction of these thalassinideans. The population biology of this ghost shrimp was examined over a period of a year and a half to gain understanding of its life history. Seasonal variation in the proportion of individuals in each size class was observed during the study, suggesting that there may be environmental factors affecting the ghost shrimp. Additionally, a life span of approximately two years is indicated by the seasonal variation in the proportion of individuals in each size class. The population was biased toward females with a 1:1.81 male:female ratio, and the mean total length of females (68.2 mm) was larger than the males collected (54.6 mm) (P = 0.0001). Collection of ovigerous females were directly correlated with an increasing ovary width of females during the preceding months, and the total length of S. tuilobata was positively correlated with the number of eggs produced. Mean number of eggs per female S. tuilobata was 197 with a maximum of 412 eggs.


FEEDING SELECTIVITY OF ANCHOVIA CLUPEOIDES (PISCES: ENGRAULIDAE) IN THE CIÉNAGA GRANDE DE SANTA MARTA, COLOMBIAN CARIBBEAN

Guillermo Duquel* and Arturo Acero P2
1Universidad Nacional de Colombia, A.A. 1016 Invemar, Santa Marta, Colombia.
*Present address: Department of Oceanography and Coastal Sciences, Coastal Fisheries Institute, Louisiana State University, Baton Rouge, Louisiana 70803 USA, E-mail gduque@lsu.edu
2Universidad Nacional de Colombia (Instituto de Ciencias Naturales) A.A. 1016 Invemar,
Santa Marta, Colombia, E-mail aacero@email.arizona.edu

ABSTRACT  Food selection by fishes is an important piece of information for modeling food webs in aquatic ecosystem. Monthly collections were made over a twenty-four hour period between October 1995 and June 1996 to examine the feeding selectivity of the zabaleta anchovy (Anchovia clupeoides) in the coastal lagoon Ciénaga Grande de Santa Marta, NE Colombia. A total of 4,389 specimens were collected, and the abundances and weights of the stomach food items were compared with similar measures calculated from samples obtained in nearby habitats. Our results indicate that the zabaleta anchovy is planktophagous, actively selecting copepods and detritus throughout the year. Individuals also exhibit positive selectivity of fish eggs and crab zoea on a seasonal basis and at different times of the day. This species avoids cyanobacteria, diatoms, and rotifers most of the year and during most of the day and always avoids copepod nauplii, polychaete larvae, and cladocerans. It seems that selection and avoidance of the food items by the zabaleta anchovy is due mainly to its preference for prey over 125 µm.


DIET OF TRIPLETAIL, LOBOTES SURINAMENSIS, FROM MISSISSIPPI COASTAL WATERS

James S. Franks1, Katherine E. VanderKooy1, and Nikola M. Garber2
1Center for Fisheries Research and Development, College of Marine Sciences, The University of Southern Mississippi, 703 East Beach Drive, Ocean Springs, MS 39564 USA, E-mail jim.franks@usm.edu
2National Sea Grant College Program, US National Oceanic and Atmospheric Administration, 1315 East Highway, Silver Spring, Maryland 20910 USA

ABSTRACT  The diet of tripletail, Lobotes surinamensis, collected from the Mississippi Sound and Mississippi's offshore waters of the Gulf of Mexico between April and September 1995-1997, was investigated through analysis of stomach contents. Of 178 tripletail stomachs examined, 136 (76%) contained prey items, and 42 (24%) were empty. Tripletail with prey in their stomachs ranged from 183 to 787mm total length (mean 522.6 mm) and 0.14 to 10.5 kg total weight (mean 3.64 kg). The diet consisted of 32 different prey types and was comprised of shrimp, crabs, and teleost fishes which were represented by about equal number and volume of prey but differed in relative importance to the diet, with fishes having greater importance. Principal contributors to the diet were Farfantepenaeus aztecus, Callinectes sapidus, Brevoortia patronus, and Chloroscombrus chrysurus. The variety of prey in the diet suggested that tripletail fed opportunistically.


THE BIOLOGY OF WAHOO (ACANTHOCYBIUM SOLANDRI) IN THE WESTERN CENTRAL ATLANTIC

Hazel A. Oxenford1, Peter A. Murray2, and Brian E. Luckhurst3
1Centre forResource Management and Environmental Studies, University of the West Indies, Cave Hill Campus, Barbados
2OECS Environment and Sustainable Development Unit, Morne Fortuné, P.O. Box 1383, Castries, Saint Lucia
3Division of Fisheries, P.O. Box CR52, Crawl CRBX, Bermuda

ABSTRACT  This contribution summarizes aspects of the biology of the wahoo, Acanthocybium solandri (Scombridae), that are pertinent to assessment and management of this species in the western central Atlantic (WCA). In this region wahoo is a target species for both commercial and recreational fisheries, and annual landings appear to have increased steadily over the last 30 years to in excess of 2000 mt. Wahoo is believed to be migratory, but little is known of the migration patterns. Significant seasonal variation in catches within the region indicates that it is seasonally abundant in most locations. Periods of peak abundance occur from the fall through spring in the southeastern and northern Caribbean islands, and are restricted to the warmer months (late spring through early fall) in the more northerly locations (northern Gulf of Mexico, North Carolina, and Bermuda). Wahoo exhibits early sexual maturity (within the first year) and a spawning season that extends from at least May to October. Females are multiple batch spawners and are highly fecund. Limited age and growth studies indicate that it is a relatively fast-growing species, has high mortality, and probably lives for 5-6 years. Wahoo is primarily piscivorous, although some invertebrates including squids are eaten. A relatively small number of parasite species have been associated with it. There is no evidence of more than a single shared stock of wahoo in the WCA, and recent genetic studies, using RAPD markers, suggest that stock boundaries may extend beyond this region. The status of the wahoo resource in the WCA remains unclear. Reliable wahoo catch and fishing effort data from the entire WCA, improved knowledge of migration patterns, reproductive characteristics and critical habitat (e.g.. preferred spawning areas), validation of age, growth and mortality estimates, and a more comprehensive analysis of stock structure for the entire Atlantic are needed for informed wahoo stock assessment and management.


STATUS AND HABITAT CHARACTERISTICS OF THE SALTMARSH TOPMINNOW, FUNDULUS JENKINSI (EVERMANN) IN EASTERN MISSISSIPPI AND WESTERN ALABAMA COASTAL BAYOUS

Mark S. Peterson1, Gregory L. Fulling2 and Christa M. Woodley3
1Department of Coastal Sciences, The University of Southern Mississippi, 703 East Beach
Drive, Ocean Springs, MS 39564 USA, E-mail mark.peterson@usm.edu
2NOAA/NMFS, 3209 Frederic Street, Pascagoula, MS 39567
3Department of Wildlife, Fish & Conservation, Academic Surge Building, University of
California-Davis, Davis, CA 95616

ABSTRACT  The saltmarsh topminnow, Fundulus jenkinsi (Evermann, 1892), occurs sporadically along the northern Gulf of Mexico and appears to prefer Spartina habitat. Throughout its range, it is considered rare or threatened and has been placed on the US Federal Register's List of Candidate Species. In order to determine the status and habitat characteristics of this species, we examined collections from 1985-1986, 1996, 1999, and 2001 from eastern Mississippi and western Alabama. We report on 868 F. jenkinsi collected in 82 locations using 414 seine hauls and 420 Breder traps over 40 dates. Results using all collections indicated F. jenkinsi is not as abundant as other fundulids in this area but is more abundant than previously thought. We also documented the first records for this species from the Pascagoula River drainage. For the Breder trap collections only, a stepwise linear regression indicated that water temperature and salinity explained 39.7% of the variance in log (mean CPUE + 0.5) over the time of this study and this relationship was significant (ANOVA, F3.59 = 13.95, P <0.001). The equation log (mean CPUE + 0.5) = 1.623 - 0.0150 (salinity) + 0.77 (depth) - 0.0584 (water temperature) indicated that mean CPUE of F. jenkinsi was higher when salinity and water temperature were lower. Using bag seine and Breder trap data, this species was most abundant (90.7% of total) in salinities >12‰ while being mainly collected in water depths near 0.5 m and water temperatures >20.0°C. We feel the use of sampling gear designed to collect resident marsh fishes is imperative and use of other gear types and/or variation in annual rainfall and the subsequent extent and patchiness of low salinity salt marsh area from year to year may explain why this species appears rare or absent in most fish studies of the northern Gulf of Mexico. Because of its distribution in low-salinity bayou habitats, this small fundulid will probably be continually placed in situations where the habitat will be impacted due to development.


USING A MODIFIED PURSE SEINE TO COLLECT AND MONITOR ESTUARINE FISHES

Michael R. Wessel and Brent L. Winner1
Florida Fish and Wildlife Conservation Commission, Florida Marine Research Institute, 100 Eighth Avenue S.E., St. Petersburg, Florida 33701-5095, Phone (727) 896-8626, FAX
(727) 893-1271, E-mail brent.winner@fwc.state.fl.us1

Abstract  We developed a modified purse seine to sample shallow water estuarine habitats and evaluated the efficacy of using this gear as a tool for monitoring estuarine fish populations in Tampa Bay, Florida. The purse seine (183-m long, 5.2 m deep and 50-mm stretch mesh nylon throughout) was easily deployed and retrieved by a 7 m flat-bottomed, bow-driven boat with a hydraulic wench and aluminum pursing davit. Retention rates of pinfish (Lagodon rhomnboides) marked and released into 35 net sets averaged 49% (range 9-100%). Retention rates were not significantly influenced by sets over vegetated and unvegetated bottom types, various waterdepths from l-3.3m and sets with and without bycatch. We then used the modified purse seine to sample fishes at 550 randomly selected sites in Tampa Bay from January 1997 to December 1998. Sampled habitats ranged from 1.0 to 3.3 m deep and included seagrass beds and non-vegetated sand or mud bottoms. Benthic, demersal, and pelagic fishes were captured, indicating the purse seine effectively sampled the entire water column. A wide size range of fishes was collected including pre-recruitment sizes of several economically important species. The ability of purse seines to fish independent of adjacent shorelines allowed us to sample nearshore waters that included large expanses of seagrass meadow.