Lectin binding to pectoral fin of neonate little skates reared under ambient and projected-end-of-century temperature regimes.

The glycosylation of macromolecules can vary both among tissue structural components and by adverse conditions, potentially providing an alternative marker of stress in organisms. Lectins are proteins that bind carbohydrate moieties and lectin histochemistry is a common method to visualize microstructures in biological specimens and diagnose pathophysiological states in human tissues known to alter glycan profiles. However, this technique is not commonly used to assess broad-spectrum changes in cellular glycosylation in response to environmental stressors.

A novel intrauterine satellite transmitter to identify parturition in large sharks.

Determining where and when animals give birth is critical for establishing effective conservation management that protects vulnerable life stages (e.g., pregnant females and newborns) and places (e.

Diving into the vertical dimension of elasmobranch movement ecology.

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species.

Physiological markers suggest energetic and nutritional adjustments in male sharks linked to reproduction.

Energetic condition is one of the most important factors that influence fitness and reproductive performance in vertebrates. Yet, we lack evidence on how energetic states change in response to reproduction in large marine vertebrates. In the present study, we used a non-lethal approach to assess relationships among reproductive stage, circulating steroid hormones (testosterone and relative corticosteroid levels), plasma fatty acids, and the ketone body β-hydroxybutyrate in male sharks of two species with divergent ecologies, the benthic nurse shark (Ginglymostoma cirratum) and the epipelagic blacktip shark (Carcharhinus limbatus).

Metabolic and nutritional condition of juvenile tiger sharks exposed to regional differences in coastal urbanization.

How varying levels of human activity, such as proximity and size of the nearest market (i.e., market gravity), influence the nutritional ecology and physiological condition of highly migratory marine predators is poorly understood.

Combined Effects of Acute Temperature Change and Elevated CO on the Metabolic Rates and Hypoxia Tolerances of Clearnose Skate (), Summer Flounder (), and Thorny Skate ().

Understanding how rising temperatures, ocean acidification, and hypoxia affect the performance of coastal fishes is essential to predicting species-specific responses to climate change. Although a population's habitat influences physiological performance, little work has explicitly examined the multi-stressor responses of species from habitats differing in natural variability. Here, clearnose skate (Rostaraja eglanteria) and summer flounder () from mid-Atlantic estuaries, and thorny skate () from the Gulf of Maine, were acutely exposed to current and projected temperatures (20, 24, or 28 °C; 22 or 30 °C; and 9, 13, or 15 °C, respectively) and acidification conditions (pH 7.

Risk of extinction of a unique skate population due to predation by a recovering marine mammal.

Benefitting from reduced harvesting and an end to culling, many marine mammals are now recovering from past overexploitation. These recoveries represent important conservation successes but present a serious conservation problem when the recovering mammals are predators of species of conservation concern. Here, we examine the role of predation by recovering grey seals (Halichoerus grypus) in the near-extinction of a unique skate population in the southern Gulf of St.

The effect of capture and handling stress in in the scallop dredge fishery.

Capture and handling stress studies are considered a primary research priority, particularly for species and fisheries where discard rates are high, and/or for overfished stocks and species of concern. , a commercially valuable finfish in New England, constitutes the second highest bycatch species within the sea scallop dredge fishery. Despite its commercial importance, no data exists on the capture and handling stress of monkfish for any gear type.

Using circulating reproductive hormones for sex determination of Atlantic sturgeon () in the Saco River estuary, Maine.

The Atlantic sturgeon () is a long-lived, anadromous fish species ranging from Labrador, CA to Florida, USA. In the Saco River, located in the Gulf of Maine, this species was not present during a survey study ending in 1982, but was found inhabiting the estuary in 2007. Although the reason for the return of this sturgeon to this river system remains unknown, research on basic life-history information is necessary to facilitate the conservation of this federally protected species.

The use of satellite tags to redefine movement patterns of spiny dogfish (Squalus acanthias) along the U.S. east coast: implications for fisheries management.

Spiny dogfish (Squalus acanthias) are assumed to be a highly migratory species, making habitual north-south migrations throughout their northwestern Atlantic United States (U.S.) range.

Using estradiol and progesterone concentrations to assess individual variability in the reproductive cyclicity of captive female little skates, Leucoraja erinacea, from the western Gulf of Maine.

In the current study, plasma steroid hormones were used to assess the individual variability of Leucoraja erinacea over the course of 12 months, in hopes of further defining its reproductive cycle. No statistical differences in hormone concentrations were observed between the isolated and non-isolated female skates. Monthly E2 concentrations ranged from 1,430 pg ml(-1) in August to 3,940 pg ml(-1) in March, indicating the presence of mature ovarian follicles and supporting the conclusions from previous studies that L.

Assessing reproductive status in elasmobranch fishes using steroid hormones extracted from skeletal muscle tissue.

Elasmobranch fishes (sharks, skates, and rays) are particularly susceptible to anthropogenic threats, making a thorough understanding of their life history characteristics essential for proper management. Historically, elasmobranch reproductive data have been collected by lethal sampling, an approach that is problematic for threatened and endangered species. However, recent studies have demonstrated that non-lethal approaches can be as effective as lethal ones for assessment of the reproductive status of an animal.

Seasonal variations in the physiological stress response to discrete bouts of aerial exposure in the little skate, Leucoraja erinacea.

Aerial exposure and acute thermal stress have been shown to elicit profound physiological disruptions in obligate water-breathing teleosts. However, no study has investigated these responses in an elasmobranch. To address this, venous blood samples were collected and evaluated from little skates (Leucoraja erinacea) subjected to discrete aerial exposure durations (0, 15, and 50 min) coupled with differing abrupt thermal changes (gradient between seawater and air; winter: ΔT=-3 °C; summer: ΔT=+9 °C) in two distinct laboratory studies.