Morphological description and molecular characterization of Heterospinus mccordi n. gen. n. sp. (Acanthocephala: Polymorphidae) from cystacanths infecting a non-native crayfish host, Procambarus clarkii (Decapoda: Cambaridae), in South Carolina, USA.

A new genus and species within the family Polymorphidae Meyer, 1931 were erected to accommodate cystacanths recovered from the mesentery of individuals from a non-native population of the red swamp crayfish Procambarus clarkii (Girard), collected from South Carolina (USA). Morphological characteristics of the specimens collected included in both sexes a spindle-shaped body with a slender hindtrunk, two fields of markedly different sized spines on the foretrunk, the presence of a middle row of smaller scythe-shaped hooks on a proboscis armed with 19-20 longitudinal rows of 14-16 hooks; and in males, six cement glands, absence of genital spines, and a digitiform and spinose bursa (observed inverted). Sequencing portions of both the mitochondrial cytochrome c oxidase I (COI) and large subunit ribosomal RNA genes was completed, followed by phylogenetic analysis of a concatenated alignment.

Differences in Growth Performance and Meat Quality between Male and Female Juvenile Nile Tilapia () during Separate Rearing.

This study compared the growth and flesh quality of juvenile male and female Nile tilapia grown in separate RAS tanks. The Genetic Sex Determination method yielded 40 males and 40 females. Males grew longer and heavier than females, and the results showed significant variation between the sexes in terms of weight gain rate (WGR), specific growth rate (SGR), and final body length and weight.

Myxospore density of Kudoa inornata varies significantly within symmetrical white muscle tissue replicates of its fish host, the spotted seatrout, Cynoscion nebulosus.

The spotted seatrout, Cynoscion nebulosus, is a popular game fish in the southeastern USA. It is estimated that nearly 90% of the adult population in South Carolina estuaries are infected in their skeletal muscle by the myxosporean, Kudoa inornata. However, little is known about this parasite's biology, including the distribution and densities of myxospores within tissues of infected fish, which we expect affect the physiology of their hosts.

Female alternative reproductive tactics: diversity and drivers.

It is often argued that anisogamy causes alternative reproductive tactics (ARTs) to be more common in males than females. We challenge this view by pointing out logical flaws in the argument. We then review recent work on the diversity of female ARTs, listing several understudied types such as solitary versus communal breeding and facultative parthenogenesis.

Relationships of primary productivity with anuran abundance, richness, and community composition in tropical streams.

The relationship between primary productivity and diversity has been demonstrated across taxa and spatial scales, but for organisms with biphasic life cycles, little research has examined whether productivity of larval and adult environments influence each life stage independently, or whether productivity of one life stage's environment outweighs the influence of the other. Experimental work demonstrates that tadpoles of stream-breeding anurans can exhibit a top-down influence on aquatic primary productivity (APP), but few studies have sought evidence of a bottom-up influence of primary productivity on anuran abundance, species richness and community composition, as seen in other organisms. We examined aquatic and terrestrial primary productivity in two forest types in Borneo, along with amphibian abundance, species richness, and community composition at larval and adult stages, to determine whether there is evidence for a bottom-up influence of APP on tadpole abundance and species richness across streams, and the relative importance of aquatic and terrestrial primary productivity on larval and adult phases of anurans.

High microplastic and anthropogenic particle contamination in the gastrointestinal tracts of tiger sharks (Galeocerdo cuvier) caught in the western North Atlantic Ocean.

Few studies have documented microplastics (<5 mm) in shark gastrointestinal (GI) tracts. Here, we report microplastic contamination in the tiger shark (Galeocerdo cuvier), an apex predator and generalist feeder, at several different life stages. We examined seven stomachs and one spiral valve from eight individuals captured off the United States Atlantic and Gulf of Mexico coasts (eastern US) and conducted a literature review of publications reporting anthropogenic debris ingestion in elasmobranchs.

Evaluation of a hepatic biomarker of nutritional imbalance in juvenile red drum () fed 60% soybean meal-based diets using NMR-based metabolomics.

A 12-week feeding trial with juvenile red drum () fed high-soybean meal (SBM) diets was conducted to investigate a putative biomarker of nutritional imbalance, N-formimino-L-glutamate (FIGLU). Three fishmeal-free, 60% SBM pelleted diets (named B12, Fol, and Met, respectively) were tested to evaluate the effects on growth performance and tissue metabolite profiles of supplementation of vitamin B (0.012 mg/kg), folate (10 mg/kg), methionine (1 g/kg) respectively, above basal supplementation levels.

Has recombination changed during the recent evolution of the guppy Y chromosome?

Genome sequencing and genetic mapping of molecular markers have demonstrated nearly complete Y-linkage across much of the guppy (Poecilia reticulata) XY chromosome pair. Predominant Y-linkage of factors controlling visible male-specific coloration traits also suggested that these polymorphisms are sexually antagonistic (SA). However, occasional exchanges with the X are detected, and recombination patterns also appear to differ between natural guppy populations, suggesting ongoing evolution of recombination suppression under selection created by partially sex-linked SA polymorphisms.

Philopatry influences the genetic population structure of the blacktip shark (Carcharhinus limbatus) at multiple spatial scales.

Understanding how interactions among microevolutionary forces generate genetic population structure of exploited species is vital to the implementation of management policies that facilitate persistence. Philopatry displayed by many coastal shark species can impact gene flow and facilitate selection, and has direct implications for the spatial scales of management. Here, genetic structure of the blacktip shark (Carcharhinus limbatus) was examined using a mixed-marker approach employing mitochondrial control region sequences and 4339 SNP-containing loci generated using ddRAD-Seq.

Validating blueline tilefish Caulolatilus microps ages in the U.S. South Atlantic using bomb radiocarbon (F C).

Age validation is a critical component of an age-based stock assessment and subsequent species management. Our study used bomb radiocarbon analysis to validate age estimates of Blueline Tilefish Caulolatilus microps, a species for which regional stock assessment scientists have identified age validation as a high priority. We compared a C.

Low recruitment drives the decline of red porgy (Pagrus pagrus) along the southeast USA Atlantic coast: Inferences from fishery-independent trap and video monitoring.

Red porgy (Pagrus pagrus) is a reef-associated, economically-important, winter-spawning, protogynous Sparidae species that appears to have declined in abundance in recent years along the southeast United States Atlantic coast. We used spatially-explicit generalized additive models built with fishery-independent chevron trap (1990-2021) and video data (2011-2021) to quantify the ways in which red porgy relative abundance and mean size varied across temporal, spatial, environmental, and habitat variables. Mean red porgy relative abundance from traps declined by 77% between 1992 and 2021, and declines were similarly large (69%) on video between 2011 and 2021.

Overwintering and breeding patterns of monarch butterflies (Danaus plexippus) in coastal plain habitats of the southeastern USA.

Understanding variability in species' traits can inform our understanding of their ecology and aid in the development of management and conservation strategies. Monarch butterflies (Danaus plexippus) are native to the western hemisphere and are well-known for their long-distance migrations but have experienced significant population declines in recent decades. Here we use a 5-year capture-mark-recapture dataset to compare monarch distributions, mating activity, and larval host plant use between two coastal plain habitats in South Carolina, USA.

An Assessment of Southeast United States Headwater Tidal Creek Sediment Contamination Over a Twenty-Year Period in Relation to Coastal Development.

Headwater tidal creeks are a primary link between estuarine and upland habitats, serving as conduits for runoff. They are sentinel habitats, providing early warning of potential harm, thus ideal systems to evaluate the effects of coastal suburban and urban development on environmental quality. Estuarine sediments have concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) that are associated with human activity.

Infection of Atlantic tripletail (Teleostei: Lobotidae) by brain metacercariae (Digenea: Strigeidae).

Three juvenile Atlantic tripletail caught opportunistically in Charleston Harbor (South Carolina, USA) and maintained in captivity for over three months displayed an altered swimming behavior. While no direct causation can be demonstrated herein, fish were infected in their brain by strigeid trematode larvae (metacercariae) of , which were identified via ITS2 and 28S ribosomal RNA gene sequencing Histology showed nonencysted metacercariae within the brain ventricle between the optic tectum and tegmentum, causing distortion of tegmental parenchyma. Aggregates of mononuclear inflammatory cells were in the ventricle adjacent to metacercariae.

Epigenetic and Genetic Population Structure is Coupled in a Marine Invertebrate.

Delineating the relative influence of genotype and the environment on DNA methylation is critical for characterizing the spectrum of organism fitness as driven by adaptation and phenotypic plasticity. In this study, we integrated genomic and DNA methylation data for two distinct Olympia oyster (Ostrea lurida) populations while controlling for within-generation environmental influences. In addition to providing the first characterization of genome-wide DNA methylation patterns in the oyster genus Ostrea, we identified 3,963 differentially methylated loci between populations.

Ontogenetic and spatial variability in parasite communities of white shrimp (Decapoda: Penaeidae).

Understanding the combined effects of multi-parasite infections on their hosts is necessary for documenting parasite impacts and is particularly important for developing effective management strategies for economically important organisms. The white shrimp supports important recreational and commercial fisheries along the southeastern and Gulf coasts of the United States and occupies an important ecological niche in estuarine and offshore habitats throughout these regions. The goal of this study was to identify and assess ontogenetic and spatial variation in white shrimp parasite communities and their relation to shrimp health.

Vertical space use and thermal range of the great hammerhead (Sphyrna mokarran), (Rüppell, 1837) in the western North Atlantic.

The great hammerhead (Sphyrna mokarran) is a highly mobile, large-bodied shark primarily found in coastal-pelagic and semi-oceanic waters across a circumtropical range. It is a target or by-catch species in multiple fisheries, and as a result, rapid population declines have occurred in many regions. These declines have contributed to the species being assessed as globally critically endangered on the IUCN Red List.

Partial sex linkage and linkage disequilibrium on the guppy sex chromosome.

The guppy Y chromosome has been considered a model system for the evolution of suppressed recombination between sex chromosomes, and it has been proposed that complete sex-linkage has evolved across about 3 Mb surrounding this fish's sex-determining locus, followed by recombination suppression across a further 7 Mb of the 23 Mb XY pair, forming younger "evolutionary strata". Sequences of the guppy genome show that Y is very similar to the X chromosome. Knowing which parts of the Y are completely nonrecombining, and whether there is indeed a large completely nonrecombining region, are important for understanding its evolution.

Hexabothriidae and Monocotylidae (Monogenoidea) from the gills of neonate hammerhead sharks (Sphyrnidae) , and their hybrids from the western North Atlantic Ocean.

Neonates of hammerhead sharks (Sphyrnidae), (Griffith and Smith, 1834), the sympatric cryptic species, Quattro ., 2013, and their hybrids were captured in the western North Atlantic, along the coast of South Carolina, USA, between 2018 and 2019 and examined for gill monogenoids. Parasites were identified and redescribed from the gills of 79 neonates, and DNA sequences from partial fragments of the nuclear 28S ribosomal RNA (rDNA) and cytochrome c oxidase I mitochondrial DNA (COI) genes were generated to confirm species identifications.

Chronic exposure to high-density polyethylene microplastic through feeding alters the nutrient metabolism of juvenile yellow perch ().

Microplastics are emergent contaminants threatening aquatic organisms including aquacultured fish. This study investigated the effects of high-density polyethylene (HDPE, 100 to 125 μm) on yellow perch () based on integrative evaluation including growth performance, nutritional status, nutrient metabolism, fish health, and gut microbial community. Five test diets (0, 1, 2, 4, or 8 g HDPE/100 g diet) containing 41% protein and 10.

Multiple paternity in two populations of finetooth sharks () with varying reproductive periodicity.

The mechanisms underlying polyandry and female mate choice in certain taxonomic groups remain widely debated. In elasmobranchs, several species have shown varying rates of polyandry based on genetic studies of multiple paternity (MP). We investigated MP in the finetooth shark, , in order to directly test the encounter rate hypothesis (ERH), which predicts that MP is a result of the frequency of encounters between mature conspecifics during the breeding season, and should therefore increase when more time is available for copulation and sperm storage.

Mercury accumulation in reef fishes: a comparison among red grouper, scamp, and gag of the Atlantic southeastern US and evaluation of "grouper" consumption guidelines.

In fish consumption advisories pertaining to Hg, grouper species in the family Serranidae are often lumped together and labeled generically as Grouper. However, grouper species vary considerably in growth rate, maximum age, and maximum size. This study examined the variability of Hg concentrations and bioaccumulation rates (increase of Hg concentrations in relation to age) for populations of three long-lived, slow-growing, protogynous hermaphrodite grouper species, gag Mycteroperca microlepis, scamp M.

A rapid phenotype change in the pathogen Perkinsus marinus was associated with a historically significant marine disease emergence in the eastern oyster.

The protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo's intensification or the persistence of its intensified activity.

Health and nutrition of loggerhead sea turtles (Caretta caretta) in the southeastern United States.

Loggerhead sea turtles (Caretta caretta) are opportunistic carnivores that feed primarily on benthic invertebrates and fish. Sea turtle rehabilitation requires provision of a species-specific, balanced diet that supplies nutrition similar to that of a wild diet; this can be challenging because free-ranging loggerheads' diets vary depending on their life stage and geographic location, with predominant prey species dictated by local availability. The goal of this study was to better understand the nutritional needs of subadult and adult loggerheads in rehabilitation.