Christopher M. Pomory

Color development time of the Lowry protein assay.

Color development of the Lowry protein assay was tracked over time for bovine serum albumin (BSA) concentrations ranging from 40 to 600 microg/ml. The time interval between 2 and 4h produced the most stable readings. This time frame also improved linearity of the standard curve.

Diel temperature patterns of juvenile lemon sharks Negaprion brevirostris, in a shallow-water nursery

The relatively complex pattern of temperature selection exhibited by juvenile lemon sharks Negaprion brevirostris in the North Sound differed markedly from many previously described responses of fish preferenda. Thermal data demonstrated that juvenile N. brevirostris did not attempt to behaviourally maintain a constant eccritic temperature. Rather, juveniles selected progressively warmer temperatures throughout the day until reaching the highest temperatures available, and then moved to cooler temperatures during late evening and early morning hours. It is possible that by exploiting habitat thermal heterogeneity juvenile N. brevirostris prolong activities such as feeding or digestion well into the cooler parts of the evening. The complex pattern of temperature occupation by juvenile N. brevirostris within the thermally heterogeneous North Sound nursery is probably linked to key daily activities such as prey capture, predator avoidance and digestive efficiency.

Thermal Tolerance and Metabolic Responses of Two Damselfish Species from a Hyperthermic Rockpool Nursery in Dry Tortugas National Park, USA

Abstract Beachrock formations on Loggerhead Key in Dry Tortugas National Park, USA are an important nursery for many juvenile reef fishes. Wide variations in temperature are common in these areas and can markedly influence fish metabolism and thermal tolerance. We determined routine resting metabolic rate and temperature quotient (Q10) at 24 and 32°C. Thermal tolerance (measured as critical thermal maximum, CTmax) was also measured for sergeant major (Abudefduf saxitilis) and cocoa damselfish (Stegastes variabilis) acclimatized to beachrock nursery temperatures. Sergeant majors occupied shallow rockpool margins that experience rapid, extreme temperature changes. These fish exhibited relatively low metabolic rates, reduced Q10 values (2.40), and relatively high levels of temperature tolerance (CTmax = 40.0°C). Cocoa damselfish selected deeper, more thermally stable rockpool areas. These fish had higher metabolic rates, were more sensitive to temperature increase (Q10 = 2.84), and were less tolerant of high temperatures (CTmax = 38.6°C) than sergeant majors. Metabolic and temperature tolerance adaptations of juvenile sergeant majors and cocoa damselfish allow these fishes to exploit a variety of microhabitats found in beachrock areas on Loggerhead Key.

A Comparison of Damselfish Densities on Live Staghorn Coral {Acropora cervicornis) and Coral Rubble in Dry Tortugas National Park

Abstract Over the past 30 years, cold events and disease have reduced much of the live Acropora cervicornis (Staghorn Coral) in Dry Tortugas National Park (DTNP), FL to fields of coral rubble. It is unclear how the resulting loss of three-dimensional reef structure has affected density and distribution of reef-dependent damselfishes. We compared densities of Stegastes adustus (Dusky Damselfish), Stegastes leucostictus (Beaugregory Damselfish), Microspathodon chrysurus (Yellowtail Damselfish), Stegastes planifrons (Three-spot Damselfish) and Stegastes variabilis (Cocoa Damselfish) inhabiting DTNPs last live Staghorn Coral formation with densities from surrounding coral rubble. Live Staghorn Coral supported a 65% higher damselfish density compared to coral rubble. Density of Dusky, Cocoa, Beaugregory, Yellowtail and Three-spot Damselfish on coral rubble (0.11, 0.58, 0.74, 0.02, and 0.06 fish/m2, respectively) was less than that found on living Staghorn Coral colonies (2.03, 0.45, 0.25, 0.50, and 0.96 fish/m2, respectively). Dusky Damselfish dominated the live Staghorn Coral site, while Cocoa and Beaugregory Damselfish dominated the coral rubble site. Juvenile density was ten times greater on coral rubble than on live Staghorn Coral, whereas adults had highest densities on live Staghorn Coral.

Salinity effects on arm regeneration in Luidia clathrata (Echinodermata: Asteroidea)

The effect of salinity (20, 25, and 30 psu) on regeneration of two arms of adult starfish Luidia clathrata (n = 8 per salinity treatment group collected from Pensacola Bay, Florida, USA 30° 20′ N, 87° 13′ W) was examined in a laboratory experiment (November 2009 to March 2010) to test the hypothesis that L. clathrata is adapted to euryhaline conditions found in bays with regards to arm regeneration. Regenerating arm condition (lengths and weights) relative to treatment was 20-psu treatment < 25-psu treatment < 30-psu treatment, and non-regenerating arm condition was 20-psu treatment < 25-psu treatment = 30-psu treatment. Luidia clathrata is not adapted to lower salinity conditions found in bays with regard to arm regeneration, despite the common occurrence of the species in bays. Lower salinity in bays should reduce the ability of L. clathrata to recover from damage sustained during, or just prior to, low-salinity periods.

A note on calculating P values from 0.15–0.005 for the Anderson-Darling normality test using the F distribution

Abstract Exact P values in the range 0.15–0.005 for the Anderson-Darling statistic can be calculated using the F distribution by modifying the asymptotic statistic A* with a simple formula. The formula calculates F* and P is calculated using .

Effects of bleaching and nutrient supplementation on wet weight in the jellyfish Cassiopea xamachana (Bigelow) (Cnidaria: Scyphozoa)

Cassiopea xamachana were bleached by elevated temperature or held in complete darkness. Wet weight was measured over several weeks in bleached and unbleached individuals with or without addition of dissolved organic matter (DOM) and/or particulate organic matter (POM) in a three-factor experiment. Wet weight decreased to a greater extent in temperature-bleached individuals compared to unbleached individuals. Bleaching by darkness produced differences that took longer to manifest themselves compared with temperature bleaching suggesting more than just loss of photosynthetic capability results from heat bleaching. No differences were found between jellyfish based on DOM and/or POM treatments. Heat stress combined with loss of zooxanthellae negatively effects C. xamachana over short time spans indicating the potential for this species to be impacted by natural bleaching events. Cassiopea xamachana could also be a useful model for further study of the effects of bleaching and the recovery.

Density of Diadema antillarum (Echinodermata: Echinoidea) on Live Coral Patch Reefs and Dead Acropora cervicornis Rubble Patches Near Loggerhead Key, Dry Tortugas National Park, Florida, USA

Abstract Density of adult Diadema antillarum was assessed on live coral patch reefs and dead Acropora cervicornis rubble patches next to Loggerhead Key, Dry Tortugas National Park, Florida, USA in June 2009. Mean density on live coral patch reefs (0.49 individuals m-2) was not statistically different from mean density on dead A. cervicornis rubble patches (0.30 individuals m-2), while the highest density on live coral patch reefs (1.39 individuals m-2) was twice that of dead A. cervicornis rubble patches (0.63 individuals m-2). A significant negative correlation was found between two-dimensional area and density of adult D. antillarum on live coral patch reefs, while no significant correlation was found between two-dimensional area and density of D. antillarum on dead A. cervicornis rubble patches. No significant correlation was found between rugosity and density of D. antillarum on dead A. cervicornis rubble patches. While adult densities are higher than after the mass mortality event of the 1980s, they have not recovered to pre-mass mortality levels. The ability of D. antillarum to occupy completely dead rubble may help in the long-term reestablishment of the species on live reefs by allowing it to utilize additional areas for possible spawning and juvenile recruitment.