Naked goby

The South Carolina Department of Natural Resources published guides to many threatened animals living in the state. This guide gives information about the Naked goby, including description, status, habitat, conservation challenges & recommendations, and measures of success

Interannual Variation In The Recruitment Pattern And Abundance Of Age-0 Summer Flounder, Paralichthys-Dentatus, In Virginia Estuaries

Capture of transforming larval and newly settled juvenile (age-0) summer flounder, Paralichthys dentatus, over four years (1986-1989) in the seaside salt marshes of Virginia\u27s Eastern Shore and in the lower Chesapeake Bay verifies Virginia waters as a nursery area. Gear specific for juvenile flatfish was used and sampling was conducted in a broad range of habitats in all months. This study demonstrates a fluctuation in the timing of the appearance and magnitude of abundance of age-0 summer flounder in Virginia waters over a four-year sampling period. Age-0 summer flounder (11-27 mm TL) began entering the area in October 1986 and were present throughout the winter of 1987. The 1988 and 1989 year classes did not appear until April at larger sizes (22-83 mm TL). Highest catch per unit of effort (CPUE) occurred between April and August and abundance declined in the fall. Data indicated that year-class strength declined from 1986 to 1988 and increased slightly in 1989. To monitor year-class strength of age-0 summer flounder, we recommend sampling Virginia estuaries in April, May, and June when both abundance of flounder is high and small-mesh-lined trawl gear is most efficient

Reproductive seasonality, maturation, fecundity, and spawning frequency of the vermilion snapper, Rhomboplites aurorubens, off the southeastern United States

Vermilion snapper, Rhomboplites aurorubens, is an important species in headboat and commercial reef fisheries in the southeastern United States, especially in the Carolinas. The reproductive biology of vermilion snapper was determined from samples collected on biweekly research cruises (April to August 1992 and May 1993) and from samples collected from commercial vessels (September to April 1992-93). Vermilion snapper did not exhibit a 1:1 sex ratio; 63% of the specimens were female. The reproductive season of vermilion snapper is April through late September in the southeastern United States. All vermilion snapper examined were mature, with the smallest female at 165 mm FL, the smallest male at 179mm FL. The smallest fish aged (165 mmFL) was two years old. Length was the best predictor of batch fecundity lBF=O.0438FL2.5081. Vermilion snapper spawn approximately every five days or about 35 times a year. Atresia did not significantly affect fecundity estimates. Vermilion snapper is an indeterminate spawner; its oocytes mature continuously during the spawning season and there is no hiatus between the size distribution of the oocyte classes. Total fecundity did not decline over the spawning season. Rather, it gradually increased through August and then declined in September. Mean oocyte diameter stayed constant over the reproductive season. The order of spawning batches was not consistent with the determinate fecundity prediction

Further Evidence for the Invasion and Establishment of Pterois volitans (Teleostei: Scorpaenidae) Along the Atlantic Coast of the United States

We document the continues population expansion of red lionfish, Pterois volitans, the first documented successful introduction of an invasive marine fish species from the western Pacific to Atlantic coastal water of the United States. Red lionfish are indigenous to the Indo-Pacific and have apparently established one or more breeding population on reefs off the southeastern United States. Fifty-nine specimens, most presumably adult red lionfish, were documented or collected on live-bottom reefs North Carolina, South Caroline, and Florida, and on a manmade structure off Georgia. Observation/collection depths and bottom water temperatures for these fish ranged from 4-99 m and 13.8-24.4 o c, respectively. Eleven juvenile lionfish, believed to be expatriated from southeastern waters, were collected in estuaries along the coast of Long Island, NY, at depths of 0-5 m and water temperatures ranging from 13.8-16.5 oC. Twelve of the total 70 specimens collected or observed were positively identified as red lionfish. Based on histological assessment of gonad tissue, two reproductively-active males and one immature female were collected. The life history of red lionfish, especially their reproductive biology and food habits, should be investigated along the east coast of the US to determine the potential impacts of the species on ecosystems they have invaded

Emerging issues and methodological advances in fisheries reproductive biology

Although incorporating detailed reproductive data into all stock assessments is not a practical goal, the need to understand how reproductive biology affects population productivity is being increasingly recognized. More research focused on reproductive biology—coupled with a shift towards a resilience perspective in fisheries science—is resulting in challenges to many long-held assumptions; the emergence of important new issues; and identification of the need to improve data and methods used in reproductive studies. Typically, data for reproductive studies are based on an assessment of gonadal development, which is most accurately evaluated with histology. This special section of Marine and Coastal Fisheries contains contributions from a workshop on the gonadal histology of fishes that was held in Cadiz, Spain, during June 2009. These papers cover a wide range of species and reproductive topics while introducing improved and new histological techniques. In this introduction, we address the following needs: (1) to employ standardization, thereby improving our ability to conduct comparative studies; (2) to better understand patterns of gonadal development and spawning events over time; and (3) to move beyond the spawning stock biomass paradigm. We identify the contributions of special section papers to these topics and conclude by suggesting needsThis workshop was jointly sponsored by FRESH (COST Action FA0601; www.fresh-cost.org) and the AFS Marine Fisheries Section.Peer reviewe

Review of size- and age-dependence in batch spawning : implications for stock assessment of fish species exhibiting indeterminate fecundity

Most assessments of fish stocks use some measure of the reproductive potential of a population, such as spawning biomass. However, the correlation between spawning biomass and reproductive potential is not always strong, and it likely is weakest in the tropics and subtropics, where species tend to exhibit indeterminate fecundity and release eggs in batches over a protracted spawning season. In such cases, computing annual reproductive output requires estimates of batch fecundity and the annual number of batches—the latter subject to spawning frequency and duration of spawning season. Batch fecundity is commonly measured by age (or size), but these other variables are not. Without the relevant data, the annual number of batches is assumed to be invariant across age. We reviewed the literature and found that this default assumption lacks empirical support because both spawning duration and spawning frequency generally increase with age or size. We demonstrate effects of this assumption on measures of reproductive value and spawning potential ratio, a metric commonly used to gauge stock status. Model applications showed substantial sensitivity to age dependence in the annual number of batches. If the annual number of batches increases with age but is incorrectly assumed to be constant, stock assessment models would tend to overestimate the biological reference points used for setting harvest rates. This study underscores the need to better understand the age or size-dependent contrast in the annual number of batches, and we conclude that, for species without evidence to support invariance, the default assumption should be replaced with one that accounts for age- or size-dependence

Identification of larval sea basses (Centropristis spp.) using ribosomal DNA-specific molecular assays

This paper is not subject to U.S. copyright. The definitive version was published in Fishery Bulletin 106 (2008): 183-193.The identification of sea bass (Centropristis) larvae to species is difficult because of similar morphological characters, spawning times, and overlapping species ranges. Black sea bass (Centropristis striata) is an important fishery species and is currently considered to be overfished south of Cape Hatteras, North Carolina. We describe methods for identifying three species of sea bass larvae using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) assays based on species-specific amplification of rDNA internal transcribed spacer reg ions. The assays were tested against DNA of ten other cooccurring reef fish species to ensure the assay’s specificity. Centropristis larvae were collected on three cruises during cross-shelf transects and were used to validate the assays. Seventysix Centropristis larvae were assayed and 69 (91%) were identified successfully. DNA was not amplified from 5% of the larvae and identification was inconclusive for 3% of the larvae. These assays can be used to identify sea bass eggs and larvae and will help to assess spawning locations, spawning times, and larval dispersal.Collection of larvae at sea was supported by funding from the National Science Foundation through OCE 9876565 to C. Jones, S. Thorrold, A. Valle-Levinson, and J. Hare. Additional funding for this project was provided by Office of National Marine Sanctuaries and by Grays Reef National Marine Sanctuary

A standardized terminology for describing reproductive development in fishes

19 páginas, 12 figuras, 3 tablas.-- Open access journalAs the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This has made it difficult for both scientists and resource managers to communicate and for comparisons to be made among studies.We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and female elasmobranch and teleost fishes. These phases were chosen because they define key milestones in the reproductive cycle; the phases include immature, developing, spawning capable, regressing, and regenerating. Although the temporal sequence of events during gamete development in each phase may vary among species, each phase has specific histological and physiological markers and is conceptually universal. The immature phase can occur only once. The developing phase signals entry into the gonadotropin-dependent stage of oogenesis and spermatogenesis and ultimately results in gonadal growth. The spawning capable phase includes (1) those fish with gamete development that is sufficiently advanced to allow for spawning within the current reproductive cycle and (2) batch-spawning females that show signs of previous spawns (i.e., postovulatory follicle complex) and that are also capable of additional spawns during the current cycle. Within the spawning capable phase, an actively spawning subphase is defined that corresponds to hydration and ovulation in females and spermiation in males. The regressing phase indicates completion of the reproductive cycle and, for many fish, completion of the spawning season. Fish in the regenerating phase are sexually mature but reproductively inactive. Species-specific histological criteria or classes can be incorporated within each of the universal phases, allowing for more specific divisions (subphases) while preserving the overall reproductive terminology for comparative purposes. This terminology can easily be modified for fishes with alternate reproductive strategies, such as hermaphrodites (addition of a transition phase) and livebearers (addition of a gestation phase)Fish Reproduction and Fisheries (FRESH; European Cooperation in Science and Technology Action FA0601) and theWest Palm Beach Fishing Club (Florida) provided funding for the gonadal histology workshops where this terminology was developed and refined. Additionally, we thank FRESH for travel and publication fundsPeer reviewe