Life Sciences Commons^™

The Status Of Spotted Seatrout (Cynoscion Nebulosus) As A Technologically Feasible Species For U.S. Marine Aquaculture, Reginald Blaylock, Eric Saillant, Angelos Apeitos, David Abrego, Paul Cason, Robert Vega

Faculty Publications

Culture models and facilities for large-scale, commercial production of popular Gulf of Mexico species are unavailable. The spotted seatrout (Cynoscion nebulosus) is one of the most popular recreational fishes in the Gulf of Mexico. Seatrout culture techniques were adapted from red drum (Sciaenops ocellatus) protocols developed in the 1970s. Broodstock husbandry, spawning, and extensive pond rearing techniques using fertilized and bloomed brackish ponds were well-established by the 1980s. By 2018, approximately 80 million 25–30-day old seatrout had been produced, mainly for stock enhancement. Cannibalism and poor nutrition hindered intensive tank culture. Between 2005 and 2015, an …

Regional Patterns In The Otolith Chemistry Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) Differ Under Contrasting Hydrological Regimes, Chet F. Rakocinski, Bruce H. Comyns, Mark S. Peterson, Alan M. Shiller

Faculty Publications

The value of using otolith chemistry to characterize recruitment in terms of natal source regions depends on how consistently spatio-temporal variation can be resolved. The objective of this study was to compare regional classification patterns in the otolith chemistry of juvenile Spotted Seatrout (Cynoscion nebulosus) between two years experiencing disparate hydrological regimes, and separated by a five year interlude. Spatial patterns in the whole-otolith chemistry of juveniles of this estuarine-dependent species were compared between years using five otolith elements and two stable isotopes. Consistent size-related trends in uptake and deposition were evidenced by parallel ontogenetic relationships for six otolith variables. …

Habitat Characterization, Habitat Use And Associated Growth Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) In A Mississippi Bay System: Implications For Stock Enhancement Practices, Joseph Read Hendon

Dissertations

The spotted seatrout (Cynoscion nebulosus) is the most targeted recreational fishery species in Mississippi coastal waters. Consequently, the Seatrout Population Enhancement Cooperative stock enhancement program was initiated to investigate methods for supplementing this heavily exploited population. Given ecological data needs for both wild and hatchery-reared (HR) juveniles of the species, habitat mapping, directed sampling and a caging study were conducted. Submerged aquatic vegetation (SAV), oyster shell and non-vegetated substrates were mapped at water depths < 2 m in Point aux Chenes Bay, Mississippi, using a sidescan sonar, which provided more accurate estimations of habitat coverage, particularly for SAV, compared to point-based sampling. Applying habitat strata delineated from sidescan mapping, late-juvenile spotted seatrout [125 - 275 mm total length (TL)] were sampled in SAV, marsh-edge and non-vegetated habitats as part of a seasonal gill net survey conducted in 2011 and 2012. Spotted seatrout ranging from 138 to 485 mm TL were collected using a smallmesh gill net, and 65% of collected individuals fell within the targeted late-juvenile size range. Overall mean catch-per-unit-effort of C. nebulosus did not differ for abundance or biomass between years, but both metrics were significantly higher in SAV habitats. Employing cage enclosures that …

Evaluating Management Actions For Spotted Seatrout, Cynoscion Nebulosus, In Mississippi With An Age-Structured Projection Model, Richard S. Fulford, J. Read Hendon

Gulf and Caribbean Research

Spotted seatrout, Cynoscion nebulosus, is an important recreational fishery in the coastal waters of the Gulf of Mexico and is the most sought after gamefish in coastal Mississippi. The management of C. nebulosus is state-specific, and unlike other similarly managed species, data on both population structure and movement support the existence of local sub-stocks. It is important for each state to clearly examine its own sub-stock in the context of its own state fishery in order to properly manage for local sustainability. We used an age-structured assessment model to examine the status (1993–2005) of the Mississippi C. nebulosus population …

Experimental Population Dynamics Of Amyloodiniumocellatum In The Spotted Seatrout, Cynoscion Nebulosus, And The Red Snapper, Lutjanus Campechanus, Ignacio Masson

Dissertations

Amyloodinium ocellatum is a parasitic dinoflagellate that infects warm water marine bony fishes and causes high mortalities in aquaculture settings. It has three life history stages: the feeding trophont, the reproductive tomont, and the infective dinospore. This dissertation describes the characteristics of A. ocellatum infections in juvenile spotted seatrout, Cynoscion nebulosus, and red snapper, Lutjanus campechanus, studies the survival and fecundities of the stages in the life cycle of the parasite and presents a population model for A. ocellatum.

At 25°C and 33 ppt, the peak of trophont detachment occurred on day 2 postinfection in spotted seatrout and day 3 …

Cryopreservation Of Sperm Of Spotted Seatrout (Cynoscion Nebulosus), William R. Wayman, R. Glenn Thomas, Terrence R. Tiersch

Gulf and Caribbean Research

Cryopreservation of fish sperm has applications in preserving genetic resources from stocks of endangered fishes, replenishing fisheries, reducing the number of males needed in hatchery situations, and allowing repeated spawning of specific males. As part of a larger study on artificial breeding of sciaenid fishes, we developed procedures for collection, handling, refrigerated storage, and cryopreservation of spotted seatrout sperm. Hanks' balanced salt solution (HBSS) was used as an extender for collection and storage of sperm. Sperm motility in relation to graded concentrations of HBSS was used to determine the osmolality at which sperm were activated. Based on these findings, HBSS …

A Survey Of Population Characteristics For Red Drum And Spotted Seatrout In Louisiana, John M. Wakeman, Paul R. Ramsey

Gulf and Caribbean Research

Red drum and spatted seatrout stocks were sampled from seven separate study areas along the Louisiana coast and from one estuarine area in Texas, with additional intensive temporal (monthly) and microgeographic (range of salinity regimes) samplings being carried out in one Louisiana study area. Condition coefficients, which did not appear to be affected by salinity regimes within the microgeographic sampling area, varied significantly according to study area, with Texas fish showing significantly lower condition coefficients than Louisiana fish. Van Bertalanffy growth equations were fitted and annual mortality rates were estimated to obtain preliminary estimates of yields, population numbers, and densities …

Yield-Per-Recruit Of Spotted Seatrout, Richard E. Condrey, Gerald Adkins, Michael W. Wascom

Gulf and Caribbean Research

A von Bertalanffy growth curve,

L = 65.47 cm (1 - e^{-.2005 (t + .4113 yr)}),

is derived from published data on spotted seatrout in the U.S. Gulf of Mexico and used in constructing a yield-per-recruit contour. Maximum yield-per-recruit is approached as F increases above 1 and age of first entry approaches 3.9 years (14.9 in., 1.1 lb). A linear regression is derived relating average size of capture to gill net mesh size (MS in inches),

L = 1.97 in. + 8.63 MS,

and used along with legal sizes of first harvest to evaluate the impact of current …

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 …