Fish Biology

Aim The aim of this study was to resolve the evolutionary history, biogeo-graphical barriers and population histories for sister species of wrasses, the African Coris (Coris cuvieri) in the Indian Ocean and Red Sea, and the Yellow-tail Coris (Coris gaimard) in the Pacific Ocean. Glacial sea level fluctuations during the Pleistocene have shaped the evolutionary trajectories of Indo-Pacific marine fauna, primarily by creating barriers between the Red Sea, Indian Ocean and Pacific Ocean. Here, we evaluate the influence of these episodic gla-cial barriers on sister species C. cuvieri and C. gaimard. Location Red Sea, Indian Ocean, Pacific Ocean. Methods Sequences from mitochondrial DNA cytochrome oxidase c subunit I (COI), and nuclear introns gonadotropin-releasing hormone (GnRH) and ribo-somal S7 protein were analysed in 426 individuals from across the range of both species. Median-joining networks, analysis of molecular variance and Bayesian estimates of the time since most recent common ancestor were used to resolve recent population history and connectivity. Results Cytochrome oxidase c subunit I haplotypes showed a divergence of 0.97% between species, and nuclear alleles were shared between species. No population structure was detected between the Indian Ocean and Red Sea. The strongest signal of population structure was in C. gaimard between the Hawai-ian biogeographical province and other Pacific locations (COI / ST = 0.040– 0.173, P < 0.006; S7 / ST = 0.046, P < 0.001; GnRH / ST = 0.022, P < 0.005). Time to most recent common ancestor is c. 2.12 Ma for C. cuvieri and 1.76 Ma for C. gaimard. Main conclusions We demonstrate an Indian-Pacific divergence of c. 2 Myr and high contemporary gene flow between the Red Sea and Indian Ocean, mediated in part by the long pelagic larval stage. The discovery of hybrids at Christmas Island indicates that Indian and Pacific lineages have come into secondary contact after allopatric isolation. Subspecies status may be appropriate for these two wrasses.

Se evaluo el uso de antifungicos para mejorar la supervivencia embrionaria de Galaxias maculatus. Se disenaron tres tratamientos utilizando formalina en dosis de 250 ppm; yodo en dosis de 100 ppm y sal de mar en dosis de 30 ups y un tratamiento control. Para cada tratamiento y el control se utilizaron 15 replicas con 100 embriones por replica. El tratamiento correspondio a sumergir los embriones en un bano profilactico por una hora cada dos dias y el control solo en agua de salinidad 10. Posteriormente se evaluo la supervivencia larval de cada tratamiento y control a los 15 dias de vida. En el tratamiento con sal se obtuvo la mayor supervivencia embrionaria y larval, mejorando en un 27,4 y 11,6% (P 0,05) y supervivencia larval de un 16,4% menor al control (P &lt; 0,05). En conclusion la sal muestra mayor efectividad como tratamiento profilactico para mejorar la supervivencia embrionaria de G. maculatus.