A doubtful relationship between tyrosine tRNA and suppression of the vermilion mutant in Drosophila.

The conditions under which Drosophila melanogaster are grown markedly influence the amount of the hypermodified nucleoside Q found in certain tRNAs. This effect on Q biosynthesis was found in both the wild-type and the suppressor of sable [su(s)2] mutant. Suppressed vermilion flies [su(s)2v; bw] with 78% of the tyrosine tRNA in the Q-lacking (gamma) form had brown eyes indistinguishible from su(s)2v; bw flies with only 6% of the tyrosine tRNA in the gamma form. The proposal that this tRNA is a specific inhibitor or tryptophan pyrrolase in vermilion flies, and that its absence in su(s)2 flies is the mechanism of suppression is not consistent with these results. In addition, the su(s)2 locus does not seem to be primarily responsible for controlling Q biosynthesis as previously suggested

Evidence of tide pool use by a viviparous elasmobranch as a parturition site

Despite the frequent occurrence of elasmobranchs in surf zones, the use of tidal pools by these animals is unknown, with only one incidental observation reported in the literature. Here we present a possible birth observation in a tide pool for the shortnose guitarfish, Zapteryx brevirostris (Müller et Henle, 1841). We discuss this occurrence as it relates to the possible use of this micro-habitat to take advantage of its ecological characteristics during parturition, the moment of extreme vulnerability to viviparous elasmobranchs

A tangled web: global review of fishing interactions with rhino rays

Rhino rays (Order Rhinopristiformes) are one of the most threatened vertebrate groups. Despite overfishing being recognised as the greatest threat to this group, a comprehensive assessment of the fisheries and types of fishing gear that rhino rays interact with is lacking. We reviewed published and grey literature (n = 116 references) to evaluate interactions between rhino rays and fisheries, determine gear types most responsible for their capture, and species for which most interactions occur by region. Interactions (n = 420) were reported from 37 of 88 range states, for 52 of 68 known species. Combined, 59% of the literature reported interactions from trawlers and gillnets. Wedgefishes (Rhinidae) were the most reported family (29%) and bowmouth guitarfish (Rhina ancylostomus) the most reported species (9.5%). Asia accounted for half of interactions (n = 211), with 67% of the literature from unspecified gear (e.g., mixed landings), masking gear-specific interactions. Data quality was variable, with the highest resolution in countries with lower species diversity and where species are least imperiled (e.g., Australia). Discard mortality and physiological effects of capture are poorly known with data available for 25% of species (almost exclusively from Australia and the Americas). While additional data are urgently required to quantify the true extent of rhino ray catch globally, reducing fisheries mortality is a priority and key to address declining populations. Recommendations include prioritizing spatial management in critical habitats (e.g., nursery areas), expansion in the use of proven bycatch reduction devices, encouraging safe release and handling, and addressing drivers of retention and trade

Impacts of fisheries on elasmobranch reproduction: high rates of abortion and subsequent maternal mortality in the shortnose guitarfish

The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as ‘Vulnerable’ both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post-capture and post-commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture-induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non-pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species

Impacts of fisheries on elasmobranch reproduction: high rates of abortion and subsequent maternal mortality in the shortnose guitarfish

The fate of bycatch species released back into the water is crucial to estimate population status and consequent decisions to implement adequate management measurements for elasmobranchs. The shortnose guitarfish, Zapteryx brevirostris, is an endemic species of the Southwest Atlantic. It is currently listed as ‘Vulnerable’ both in the International Union for Conservation of Nature and Brazilian red lists. Although this species displays high tolerance to capture and transportation by fishers from the capture site to the fish market, a significant reduction in survival rates is observed during the reproductive period. Thus, the aim of the present study was to examine post-capture and post-commercial transportation consequences in pregnant females obtained as bycatch from artisanal fisheries in Southern Brazil. Results showed high abortion rates and reduced maternal survival after abortion, with all abortions occurring within 28 h of monitoring in laboratory. Stress plasma markers were also evaluated, to determine the physiological consequences of capture-induced parturition to pregnant females. Results showed alteration in all markers measured (plasma urea, pH, lactate, phosphorus, and potassium) with values for dead pregnant females being different from non-pregnant females and those which survived capture and subsequent abortions. The mortality caused by fisheries bycatch may prove difficult to manage, with immediate release and specific handling protocols for pregnant females implemented through environmental education environmental education and fishermen training programs, potential options to maintain adequate maternal survival and recruitment for this species.Fil: Wosnick, N.. Universidade Federal do Paraná; BrasilFil: Awruch, Cynthia Andrea. University of Tasmania; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Adams, K. R.. University Of Wollongong; AustraliaFil: Gutierre, S. M. M.. Universidade Federal do Paraná; BrasilFil: Bornatowski, H.. Universidade Federal do Paraná; BrasilFil: Prado, A. C.. Universidade Federal do Paraná; BrasilFil: Freire, C. A.. Universidade Federal do Paraná; Brasi