Black Sea Bass Centropristis Striata Research Articles

Inshore juvenile lobsters threatened by warming waters and migratory fish predators in southern New England

The southern New England stock of the American lobster Homarus americanus has declined since its peak in the 1990s. While the decline of lobsters has been directly attributed to warming sea temperatures, indirect effects such as migratory fish species shifting north may also be important. Two sets of experiments and a survey of gut contents collected from wild-caught scup Stenotomus chrysops and black sea bass Centropristis striata during the summer were performed to assess thermal and predatory stressors on juvenile lobsters. A temperature experiment compared the growth and survival of young-of-year (YOY) and 1 yr old lobsters in ambient seawater and seawater warmed or cooled by 3°C. Two predation experiments compared the survival of juvenile lobsters in treatments with scup, black sea bass, and Asian shore crabs Hemigrapsus sanguineus. Increased water temperature did not increase mortality in juvenile lobsters, but it did tend to have a negative impact on growth and weight gain of YOY lobsters and weight gain of 1 yr old lobsters. In the predation experiments, fewer lobsters survived in mesocosms with black sea bass and scup than in the control treatment. Fish gut contents contained few lobsters, but black sea bass stomachs contained many juvenile cancer crabs, signifying that the fish prey in cobble habitat that is preferred by both juvenile cancer crabs and lobsters. While juvenile lobsters can survive current temperatures, they may face compounding challenges as warmer water slows their growth and leaves them more susceptible to predation by increasing numbers of migratory scup and black sea bass.

Using otolith microchemistry to determine natal origin of Black Sea Bass off the coast of Maine

AbstractObjectiveA recent expansion of the northern stock of Black Sea Bass Centropristis striata into the northern Gulf of Maine raises questions about this species’ movement and population dynamics in this region. Determining the origin of these fish is essential, as dramatic changes in migration patterns or current population boundaries could have profound effects on stock assessment estimates and subsequent management regulations.MethodsIn this study, we measured otolith core concentrations of stable isotopes (δ18O, δ13C) and trace element:calcium ratios (Mg:Ca, Mn:Ca, Cu:Ca, Zn:Ca, Ba:Ca, Sr:Ca) to assess the natal origin of Black Sea Bass that were caught off the coast of Maine. Spawning condition adults from southern New England (SNE) and the mid‐Atlantic Bight (MAB) were used to characterize the chemical fingerprint of these known spawning regions.ResultUnique chemical fingerprints were identified for fish from SNE and the MAB, with high reclassification success using random forest analysis (16% error rate). The classification of Black Sea Bass of unknown origin that were caught in Maine waters indicated that 85% of the samples matched to SNE and 13% to the MAB, whereas one sample remained unclassified.ConclusionResults from this study support the current management population separation of the northern stock of Black Sea Bass between SNE and the MAB and lends additional information to the understanding of this species’ movement into the northern Gulf of Maine. As fish stocks around the world continue to shift into new regions due to climate change, knowledge of their natal origin will be critical to long‐term sustainable management of this species.

The Role of Fishery‐Independent Bottom Trawl Surveys in Providing Regional and Temporal Context to Offshore Wind Farm Monitoring Studies

AbstractBottom trawl surveys are commonly used to examine potential effects on fishes and invertebrates from offshore wind (OSW) farms in Europe and in the northeastern United States. Because OSW surveys typically occur over a limited spatial footprint, comparison of OSW monitoring results to long‐term fishery‐independent surveys may provide a regional and temporal context for OSW data sets. We compared results of the Block Island Wind Farm (BIWF) bottom trawl survey (2013–2019) to three fishery‐independent bottom trawl surveys (Northeast Area Monitoring and Assessment Program, Northeast Fisheries Science Center, and Rhode Island Department of Environmental Management [RIDEM]) using catch rates of 12 federally managed species. We evaluated temporal trends in annual residual catches for each species calculated within each survey as the difference between the mean annual biomass per trawl and the long‐term mean. Regional consistency in relative catches was apparent for species exhibiting synchronous interannual variability among surveys (Black Sea Bass Centropristis striata, Scup Stenotomus chrysops, Summer Flounder Paralichthys dentatus, and Winter Flounder Pseudopleuronectes americanus) or a decreasing trend in residual catch rates across the 7‐year study period (Little Skate Leucoraja erinacea, longfin inshore squid Doryteuthis pealeii, and Winter Skate L. ocellata). For other species, catches among surveys were asynchronous (Atlantic Herring Clupea harengus, Butterfish Peprilus triacanthus, and Windowpane Scophthalmus aquosus) or anomalous catches in a single year affected the results (Red Hake Urophycis chuss and Silver Hake Merluccius bilinearis). Monitoring of BIWF occurred during a period with lower‐than‐average historical catches in a 32‐year RIDEM data set for Atlantic Herring, Butterfish, Little Skate, longfin inshore squid, Red Hake, Silver Hake, and Winter Flounder and higher‐than‐average catches for Black Sea Bass, Scup, and Summer Flounder. There was no evidence that variation in catches near BIWF differed from regional trends in a way consistent with a detrimental impact of OSW farm operation. The regional context provided from multiple bottom trawl surveys varies by species and thus may be limited for interpreting OSW monitoring results.

Effectiveness of Venting and Recompression for Increasing Postrelease Survival of Barotraumatized Black Sea Bass across a Range of Depths

AbstractThe effectiveness of venting and recompression for increasing postrelease survival for fish that experience barotrauma has rarely been tested across a range of depths. We conducted a field tag–recapture experiment to test how well venting and recompression each increased postrelease survival of Black Sea Bass Centropristis striata relative to untreated controls at three different depth ranges on the U.S. South Atlantic continental shelf: 24–26, 29–32, and 35–38 m. Venting and recompression were applied by researchers alongside untreated controls at all three depths, and venting by anglers who were inexperienced with this technique was an additional treatment at the intermediate depth. Tests of independence were used to evaluate the association between treatment type (venting versus controls) and postrelease submergence at each depth. Cox proportional hazards models were fit to the tag–recapture data that were collected at each depth to determine whether the experimental treatment influenced postrelease survival. Postrelease submergence was significantly higher in vented fish at the intermediate and deep depths but not at the shallow depth. The hazards rates were not significant for venting and recompression at the shallow and intermediate depths but were at the deepest depth, demonstrating that these techniques practiced at >35 m increased postrelease survival relative to untreated controls. Mean increases in absolute survival at the 35–38 m depth were calculated to be 6.8% and 8.1% relative to controls when using venting and recompression, respectively. The results further suggest that anglers who are unfamiliar with venting do not reduce postrelease survival compared with venting by experienced personnel. These results provide guidance to fishery managers who are tasked with seeking methods to reduce catch‐and‐release mortality for an important reef species. Taken together, the findings from submergence success and survival models suggest that both venting and recompression should be encouraged to increase the postrelease survival of Black Sea Bass that are caught from depths >29 m.

Habitat and trophic niche overlap among juvenile black sea bass, tautog, and cunner: interspecific interactions amid a species geographic range expansion

Juvenile black sea bass Centropristis striata populations are increasing in southern New England estuaries of the northeastern USA with possible trophodynamic effects on labrid species: tautog Tautoga onitis and cunner Tautogolabrus adspersus. In this study, we examined the abundance, size-structure, and feeding ecology of juvenile sea bass and labrids in Narragansett Bay (Rhode Island, USA) from June to October in 2018 and 2019 and evaluated potential interspecific competition using habitat, diet, and isotopic niche overlap indices. Juveniles (age-0+) of each fish species spatiotemporally co-occurred in shallow, polyhaline habitats throughout the estuary. Age-0 cohorts were numerically dominant across species and initially recruited to the study area in July (minimum total length, TL = 15-20 mm), reached peak abundances in mid- to late summer (maximum abundances = 12-140 fish 100 m-2), and emigrated from field sites in October (maximum TL = 85-96 mm). Stomach content and stable isotope (δ15N and δ13C) analyses determined that focal fishes were generalist carnivores that foraged in bentho-pelagic food webs. Fishes also overlapped in their respective ambit and core isotopic niche space, but interspecific dietary overlap was size-dependent. Dietary overlap was most pronounced between sea bass ≤49 mm TL and labrids ≤59 mm TL due to their mutual reliance on gammarid and caprellid amphipods. Ontogenetic dietary shifts then resulted in food niche segregation, such that sea bass 50-139 mm TL consumed decapod crustaceans and fish, whereas labrids 60-181 mm TL mainly fed on amphipods, worms, bivalves, and turf-associated biota, i.e. bryozoans, hydroids, and seaweeds. Habitat and trophic niche overlap between early juvenile sea bass and labrids purportedly have not caused opposite population trajectories or food resource limitation in Narragansett Bay, indicating an absence of exploitative competition. Alternatively, realized competition between species may be too spatiotemporally restricted to alter their population dynamics. Continuous monitoring of the sea bass’s bio-ecological effects in southern New England estuaries is warranted, however, given their recent range expansion and increasing abundances at northern latitudes.

Resilience of Black Sea Bass Embryos to Increased Levels of Carbon Dioxide

AbstractAfter a decade of research on how embryonic fish will respond to the increased dissolved carbon dioxide (ρCO2) levels predicted for the next century, no uniform response to near future acidification has been observed among marine species. We exposed Black Sea Bass Centropristis striata (BSB) embryos to varied levels of ρCO2 (microatmospheres [μatm]) for 48 h during seasonal experiments conducted in 2013–2015 to compare embryonic response among multiple broodstocks. The relationship between ρCO2 concentration and hatching success was inconsistent among years, with a nonlinear, inverse relationship noted in 2014 only, explaining 13% of observed variance. Conversely, ρCO2 was a good predictor of unhatched BSB embryos after 48 h for all years combined (39%) and for 2013 (38%). The ρCO2 concentration was a good predictor of the frequency of vertebral column anomalies for individual years (2013: 40%; 2014: 12%; 2015: 38%) but not when data were pooled for all years. In 2013 and 2015, vertebral column anomalies were relatively consistent below 1,000 μatm and were elevated above that threshold. Preliminary results suggest that BSB embryos may demonstrate resilience to future ρCO2 levels, but the results also highlight the challenges associated with drawing broad conclusions given observed variability in results obtained from different broodstocks and study years.

Comparison of the Intestinal Bacteria Between Black Seabass Centropristis striata Reared in Recirculating Aquaculture System and Net Pen.

Determination of diversity and function of the bacteria in fish gut is essential to understanding the interaction between intestinal bacteria and their host organism. This study compared intestinal bacterial community of black seabass (Centropristis striata) hatched by the same breeding farm but reared in different aquaculture systems, an indoor recirculating aquaculture system (RAS) and an inshore net pen (INP). The fish were fed with formulated feed manufactured by same feed company. Bacteria in fish gut, formulated feed and seawater were identified by 16S rRNA high throughout sequencing (HTS). Total 1484 OTUs, which belonged to 34 phyla and 79 genera, were identified from fish gut, formulated feed and seawater. In fish gut, 24 phyla and 43 genera were identified. Proteobacteria, Fusobacteria, and Firmicutes dominated at the phylum level in fish gut in INP, while Proteobacteria and Firmicutes dominated in fish gut in RAS. Photobacterium, Vibrio, and Cetobacterium dominated at the genus level in fish gut in both INP and RAS. One OTU of Photobacterium occurred in all the fish gut samples, suggesting this bacterium might be the main component of the core microbiota. No significant difference was found in bacterial diversity in fish gut between INP and RAS, suggesting genetic background should be a primary factor determining intestinal bacterial community of black seabass. Bacterial diversity in seawater was high relative to that in fish gut and formulated feed, regardless in INP or RAS. The common OTU between fish gut and seawater was more than that between fish gut and formulated feed in INP, while the common OTU between fish gut and seawater was slightly less than that between fish gut and formulated feed in RAS. These results reveal that the bacteria in formulated feed and seawater could influence the bacteria in fish gut, and their priority in shaping intestinal bacterial community depended on the bacterial composition in feed and seawater. This study reveals that intestinal bacterial community of black seabass was influenced by both genetic background and environmental factors.

Evaluation of six methods for external attachment of electronic tags to fish: assessment of tag retention, growth and fish welfare.

External attachment of electronic tags has been increasingly used in fish studies. Many researchers have used ad hoc attachment methods and provided little or no validation for the assumption that tagging itself does not bias animal behaviour or survival. The authors compared six previously published methods for externally attaching acoustic transmitters to fish in a tank holding experiment with black sea bass Centropristis striata (L.). They tracked tag retention, fish growth and external trauma (as a measure of fish welfare) for 60 days. For each of these metrics, the results showed a wide range of responses among tagging treatments. A simple attachment method using a spaghetti tag passed through the dorsal musculature of the fish and tied to the end cap of the transmitter emerged as the preferred option based on high retention, no impact on growth and relatively low detriment to fish welfare. Future field studies using external electronic tagging should consider tag‐related effects that could compromise results when selecting a method for tag attachment.

Comparison of video and traps for detecting reef fishes and quantifying species richness in the continental shelf waters of the southeast USA

The management of reef-associated fish species is challenging due to their life history characteristics and occurrence in rocky reef habitats that are difficult to sample using traditional sampling gears. We compared 2 common sampling gears for reef fish species, chevron traps and underwater video, using 5 yr of comprehensive paired sampling data (N = 7034) collected at reef habitats between North Carolina and Florida along the southeast United States Atlantic continental shelf. Most fish families (80%) and species (85%) were observed significantly more often on video than caught in traps, and only 2 species out of 40 (5%)—black sea bass Centropristis striata and bank sea bass C.ocyurus—were caught significantly more often in traps than observed on video. Moreover, site-specific species richness was approximately 3-4 times higher on average for video compared to traps. We also used a generalized additive model to show that the ratio of trap-caught species to video-observed species was higher in shallower waters off North and South Carolina, especially when water clarity was low. Results demonstrate that video can be an efficient gear to sample most reef fishes around the world but may provide even greater benefits when paired with traditional sampling gears like traps to leverage the strengths of each gear for estimating relative abundance and species richness with more certainty.

Diurnal vertical movements in black sea bass (Centropristis striata): Endogenous, facultative, or something else?

AbstractFishes commonly exhibit diel rhythms in movements with consequences to feeding, reproduction, predator evasion, and resting. Such behaviors are conceived as plastic, persisting for phases (days to weeks), and then becoming disrupted, masked, and altered by changed environmental or ecological conditions. In telemetered black sea bass Centropristis striata (family Serranidae), we documented a remarkable 4‐month record of persistent diurnal vertical movements. Within the U.S. Mid‐Atlantic Bight June–October 2019 setting, biotelemetry data of 31 fish were examined through time series analysis and generalized additive modeling. Sun altitude played a dominant role throughout the series, where movements were diurnal. Thermal conditions were uniform until a September hurricane caused a 10°C rise in inhabited waters within the span of six hours, the result of water column mixing. This and other storms caused short‐term disruptions (<2 d) to diel rhythmicity. Daytime vessel traffic, but not dolphin presence, caused ≤1 h refuge‐seeking excursions. The discovery of pelagic behaviors (up to 15 m off the seabed) requires revision to the species’ natural history, which was previously conceived as exclusively demersal. Spring‐autumn movement functions included reef recruitment and evacuation, courtship and spawning, and seasonal changes in feeding ecology and predator fields. Throughout these phases, the cycle of daytime movement and nighttime inactivity persisted. We hypothesize that during the nocturnal period these visual specialists become immobile and thus evade predation and mobilize energy toward growth, reproduction, and storage. Because this function does not change from spring through autumn, we speculate that nocturnal quiescence serves as the proximate control for the diurnal activity cycle.

Implications of comparative ventral body wall histology on selection of abdominal surgical approach and closure in 12 species of fish.

A ventral midline surgical approach for fish celiotomy is commonly performed in veterinary clinical medicine and research, although the relevant ventral body wall anatomy of many fish species is not well documented. Histological evaluation of tissue samples from the ventral body wall of 12 fish species was performed to provide a reference for surgical approach and closure decisions. The width between muscle bundles running parallel to the long axis and total thickness of tissue layers varied among species. An appreciable space between longitudinal muscles of the ventral body wall and a lack of muscle, vessels and nerves on midline in all species examined supports recommendations of ventral midline incisions to spare important structures. Dense connective tissue consistent with an aponeurosis between musculature along the ventral body wall was not observed in any species evaluated. Connective tissue was concentrated within the dermis of all species evaluated, with an additional layer of collagen along the coelomic membrane in Russian sturgeon Acipenser gueldenstaedtii, koi Cyprinus carpio, goldfish Carassius auratus, black drum Pogonias cromis, black seabass Centropristis striata, tomtate Haemulon aurolineatum and scup Stenotomus caprinus. A sufficiently wide space on ventral midline for practical targeting during the surgical approach is present in A. gueldenstaedtii, C. carpio, striped bass Morone saxatilis, H. aurolineatum, P. cromis, rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta. Sand perch Diplectrum formosum, C. auratus, S. caprinus, grey triggerfish Balistes capriscus and black sea bass Centropristis striata have a negligible space between longitudinal muscles on midline. The variation in ventral body wall structure observed in this study helps inform surgical decision making for celiotomy incision and closure in these species.

Exploring video and eDNA metabarcoding methods to assess oyster aquaculture cages as fish habitat

Multi-tiered oyster aquaculture cages may provide habitat for fish assemblages similar to natural structured seafloor. Methods were developed to assess fish assemblages associated with aquaculture gear and boulder habitat using underwater video census combined with environmental DNA (eDNA) metabarcoding. Action cameras were mounted on 3 aquaculture cages at a commercial eastern oysterCrassostrea virginicafarm (‘cage’) and among 3 boulders on a natural rock reef (‘boulder’) from June to August 2017 in Long Island Sound, USA. Interval and continuous video recording strategies were tested. During interval recording, cameras collected 8 min video segments hourly from 07:00 to 19:00 h on cages only. Continuous video was also collected for 2-3 h on oyster cages and boulders. Data loggers recorded light intensity and current speed. Seawater was collected for eDNA metabarcoding on the reef and farm. MaxN measurements of fish abundance were calculated in video, and 7 fish species were observed. Black sea bassCentropristis striata, cunnerTautogolabrus adspersus, scupStenotomus chrysops, and tautogTautoga onitiswere the most abundant species observed in both oyster cage and boulder videos. In continuous video, black sea bass, scup, and tautog were observed more frequently and at higher abundance on the cage farm, while cunner were observed more frequently and at higher abundance on boulders within the rock reef. eDNA metabarcoding detected 42 fish species at the farm and reef. Six species were detected using both methods. Applied in tandem, video recording and eDNA provided a comprehensive approach for describing fish assemblages in difficult to sample structured oyster aquaculture and boulder habitats.

Evaluation of salt-incorporated diets on growth, body composition and plasma electrolytes of black sea bass Centropristis striata reared in a semi-pilot scale low salinity recirculating aquaculture system

To investigate the effects of dietary salt supplementation on growth performance, survival, body composition, and plasma electrolytes of black sea bass Centropristis striata, a feeding trial was conducted in a semi-pilot scale RAS under low salinity (10.8 ± 0.69 g L−1) rearing conditions. Four isolipidic and isonitrogenous test diets were formulated with graded levels of sea salt (99.86% NaCl): 0%, 2.5%, 5%, and 7.5% dry wt. In addition, two control diets (0% salt test diet and a premium commercial diet) were tested for fish raised in full-strength seawater (34 g L−1). Twelve tanks (vol = 2-m3) of the low-salinity RAS were each stocked with black sea bass (mean wt. = 19.6 g) at a density of 100 fish per tank and at a starting salinity of 34 g L−1 and salinity was gradually decreased (0.5 g L−1 per day) to 10.1 g L−1 in 30 days. In addition, six tanks (2-m3) of a RAS supplied with full-strength seawater were each stocked with 100 fish from the same cohort, with 3 tanks fed either of the two control diets (0% salt or the commercial diet). After the 8-month feeding trial, fish grown at low salinity were fed their respective diets for an additional 5 weeks under adverse low-salinity conditions in which salinity was further decreased gradually from 10.1 g L−1 to 4 g L−1. Survival over the 8 months remained high (93–100%) among treatments. Growth (% body weight gain) among the treatments in low salinity ranged from 766 to 825%, comparable to fish raised in full seawater (788–813%). Plasma osmolality (mOsm kg−1) for fish ranged from 336 to 357 among all treatments. However, no significant relationships between weight gain, feed conversion ratio, survival, plasma osmolality, and electrolyte concentrations and dietary salt level were observed among fish raised in low salinity. When salinity was further reduced from 10.1 g L−1 to 4 g L−1, fish fed 0% salt showed poor survival (29%), whereas fish fed 7.5% salt showed highest survival (67%), and a significant (P < 0.05) linear relationship between dietary salt and survival was observed. The results suggest that black sea bass juveniles can be raised at a low salinity of 10.1–12.3 g L−1 with no negative effects on long-term growth performance. Salt-incorporated diets, however, improved survival under extreme low salinity (~ 4 g L−1) challenge conditions. These findings have important implications for rearing black sea bass in low salinity RAS and for the siting of black sea bass RAS grow-out operations.

Overwintering survivorship and growth of young-of-the-year black sea bass Centropristis striata.

Overwintering conditions have long been known to affect fish survival and year-class strength as well as determine the poleward range limit of many temperate fishes. Despite this known importance, mechanisms controlling overwintering mortality are poorly understood and the tolerance of marine fishes to the combined effects of winter temperature, salinity, and size is rarely quantified. In recent years, higher abundances of the temperate Serranid, black sea bass Centropristis striata, have been observed at latitudes further north than their traditional range suggesting that warming water temperatures, particularly during winter, may be facilitating the establishment of a population at more northern latitudes. To examine overwintering survival of C. striata, the combined effects of temperature, salinity and body mass were quantified in laboratory experiments. We identified 6°C as the lower incipient lethal temperature for C. striata, below which fish cease feeding, lose weight rapidly and die within 32 days. A short cold exposure experiment indicated that temperatures below 5°C resulted in mortality events that continued even as the temperature increased slowly to 10°C, indicating that even short cold snaps can impact survival and recruitment in this species. Importantly, fish in lower salinity lived significantly longer than fish at higher salinity at both 3°C and 5°C, suggesting that osmoregulatory stress plays a role in overwintering mortality in this species. Size was not a critical factor in determining overwintering survival of young-of-the-year (YOY) C. striata. Overwintering survival of YOY C. striata can be effectively predicted as a function of temperature and salinity and their interaction with an accelerated failure model to project future range limits. Identifying temperature thresholds may be a tractable way to incorporate environmental factors into population models and stock assessment models in fishes.

Catchability of reef fish species in traps is strongly affected by water temperature and substrate

It is commonly assumed in surveys that the likelihood of capturing or observing individuals of a given species is constant. Yet evidence is building that catchability, or the likelihood of catching an individual present at a site, can vary. We used 5465 paired trap-video samples collected along the southeast US Atlantic coast in 2015-2018 to estimate trap catchabilities of 6 reef fish species (gray triggerfish Balistes capriscus, red porgy Pagrus pagrus, vermilion snapper Rhomboplites aurorubens, black sea bass Centropristis striata, red snapper Lutjanus campechanus, white grunt Haemulon plumierii) as the ratio of trap catch to standardized site abundance from corresponding videos. Species-specific trap catchabilities were then related to 2 primary predictor variables: water temperature and percent of the visible bottom consisting of rocky substrate. Water temperature strongly influenced trap catchabilities for all species after standardizing for all other variables. The 4 warm-water species displayed strong positive relationships between catchability and temperature; of these species, the smallest absolute increase in catchability occurred for vermilion snapper (0.0 at ~14°C to 0.05 at ~28°C) and the largest occurred for white grunt (0.0 at ~14°C to 0.49 at ~28°C). The 2 cooler-water species displayed either a dome-shaped (red porgy) or negative relationship (black sea bass) between catchability and temperature. Furthermore, trap catchabilities for all species declined substantially (42-80%) as the percent hard bottom of the site increased. Only when catchability is properly accounted for can results be considered unbiased and subsequent management advice be considered accurate.

Host, seasonal and habitat influences on incidence of Lernaeenicus radiatus (Copepoda: Pennellidae) in the mid-Atlantic Bight

Lernaeenicus radiatus is a pennellid copepod with a 2-host life cycle that exhibits high host-specificity to their first host, black sea bass Centropristis striata. This parasite was prevalent in the gills of black sea bass juveniles and adults along the coast of New Jersey, USA, April to December 2019. Parasite incidence was high in the summer and fall in near-shore areas and dropped significantly in fish from deep waters further off-shore in December. Heavy infections of L. radiatus occurred in gills of adult black sea bass inhabiting reef-associated structures, in which parasite incidence rate was 2-3.7 times higher than in non-structure habitat. Less host-specificity occurred in second hosts which support female metamorphosis. In total, 7 fish species were confirmed as second hosts, with the most common being Atlantic menhaden Brevoortia tyrannus and bay anchovy Anchoa mitchilli. Incidence of L. radiatus depends on host abundance and habitats that support interactions of the preferred fish hosts, which may explain the heavy infections in reef habitats. The L. radiatus anchor process in metamorphosed females was highly polymorphic, depending on tissue tropism. Parasite length varied considerably, with neck and trunk measurements of L. radiatus from adult menhaden being 2-4 times larger than those from smaller host species. Mitochondrial cytochrome oxidase c subunit I (COI) sequences demonstrated all parasites to be L. radiatus, with sequence divergence limited to 0.3%. These findings show that morphology of the metamorphosed females has poor taxonomic value, and polymorphisms instead are related to attachment site and host characteristics.

Black sea bass are a host in the developmental cycle of Lernaeenicus radiatus (Copepoda: Pennellidae): insights into parasite morphology, gill pathology and genetics - CORRIGENDUM.

Lernaeenicus radiatus, a mesoparasitic pennellid copepod, has long been known in the northwest Atlantic with metamorphosed females infecting the muscle of marine fish. The study herein is the first to identify a definitive first host, black sea bass Centropristis striata, for L. radiatus supporting larval development to adults and sexual reproduction in the gills. This finding suggests a two-host life cycle for L. radiatus, with black sea bass as the first host. Heavy infections in the gill were associated with considerable pathology related to a unique and invasive attachment process that penetrated the gill and selectively attached to the gill filament cartilage. The morphology of the developing copepod was highly conserved with that of a related pennellid copepod, Lernaeocera branchialis, though was distinguished by the attachment process, unique pigmentation and other morphologic features described herein. Sequencing the small and large subunits of the ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes demonstrated L. radiatus to share closer identities with Lernaeocera and Haemobaphes spp. pennellid copepods rather than other Lernaeenicus spp. available in GenBank to date. Taxonomy of L. radiatus is discussed in relation to life cycles, tissue tropism, morphology and genetics of other closely related pennellid copepods.

Carbon:nitrogen ratio as a proxy for tissue nonpolar lipid content and condition in black sea bass Centropristis striata along the Middle Atlantic Bight

Spatial and temporal variability in fish tissue lipid content may reflect resource availability, reproductive or maturity state, or environmental suitability. Here, we analyzed nonpolar (storage) lipid and morphometric condition indices of black sea bass (Centropristis striata) collected from coastal waters of the Northwest Atlantic Ocean from New Jersey to North Carolina, USA. We hypothesized that the elemental ratio of carbon to nitrogen (C:N) within C. striata white muscle and liver tissue would be a robust proxy for nonpolar lipid content (NPLC) and that NPLC would predictably covary with traditional condition indices. Further, we analyzed our NPLC tissue indices to determine how regional and biological patterns in muscle and liver NPLC aligned with traditional condition indices. Our results indicated that muscle tissue NPLC was low compared to liver tissue, and regression analysis revealed strong positive relationships between C:N and NPLC for both tissues (muscle—best fit was linear; liver—best fit was asymptotic nonlinear). Correlations of muscle and liver NPLC with other condition indices were index and region dependent (e.g., a reproductive index was positively correlated with muscle NPLC, but negatively correlated with liver NPLC). Tissue NPLC and standard condition indices differed significantly as a function of region, sex, and fish length, although the patterns were not consistent across the different indices. Our results support the use of muscle and liver C:N values to estimate tissue-specific C. striata NPLC. Further, our results indicate that NPLC indices provide additional insight into C. striata physiological condition and could assist studies examining habitat suitability across large spatial or temporal scales.

Overwintering survivorship and growth of young-of-the-year black sea bass Centropristis striata

Overwintering survivorship and growth of young-of-the-year black sea bass Centropristis striata

Black sea bass are a host in the developmental cycle of Lernaeenicus radiatus (Copepoda: Pennellidae): insights into parasite morphology, gill pathology and genetics.

Lernaeenicus radiatus, a mesoparasitic pennellid copepod, has long been known in the northwest Atlantic with metamorphosed females infecting the muscle of marine fish. The study herein is the first to identify a definitive first host, black sea bass Centropristis striata, for L. radiatus supporting larval development to adults and sexual reproduction in the gills. This finding suggests a two-host life cycle for L. radiatus, with black sea bass as the first host. Heavy infections in the gill were associated with considerable pathology related to a unique and invasive attachment process that penetrated the gill and selectively attached to the gill filament cartilage. The morphology of the developing copepod was highly conserved with that of a related pennellid copepod, Lernaeocera branchialis, though was distinguished by the attachment process, unique pigmentation and other morphologic features described herein. Sequencing the small and large subunits of the ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes demonstrated L. radiatus to share closer identities with Lernaeocera and Haemobaphes spp. pennellid copepods rather than other Lernaeenicus spp. available in GenBank to date. Taxonomy of L. radiatus is discussed in relation to life cycles, tissue tropism, morphology and genetics of other closely related pennellid copepods.