Hydrogen sulfide (H(2)S) is a recently identified endogenous vasodilator in mammals. In steelhead/rainbow trout (Oncorhynchus mykiss, Osteichthyes), H(2)S produces both dose-dependent dilation and a unique dose-dependent constriction. In this study, we examined H(2)S vasoactivity in all vertebrate classes to determine whether H(2)S is universally vasoactive and to identify phylogenetic and/or e...

Hoxa2 is an evolutionarily conserved developmental regulatory gene that functions to specify rhombomere (r) and pharyngeal arch (PA) identities throughout the Osteichthyes. Japanese medaka (Oryzias latipes) hoxa2a, like orthologous Hoxa2 genes from other osteichthyans, is expressed during embryogenesis in r2-7 and PA2-7, whereas the paralogous medaka pseudogene, ψhoxa2b, is expressed in noncano...

From January to December 2019, the composition of fish assemblages in Al-Huwyzah marsh was studied various ways based on nature their life-history strategies. In orders assess impact hydrological variations assemblage composition, diversity, and abundance. Water temperature fluctuated from 12°C 33°C July. Salinity varied 1.38 g/l March 3.87 November. Hydrogen ion 7.37 November 8.18 December. Mo...

The gills of 63 specimens of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from three localities of the Mediterranean (Sardinian, Tyrrhenian and Levantine Seas) were examined for metazoan parasites. The parasite fauna of T. thynnus from the Sea of Sardinia included 11 species: five didymozoid trematodes, three capsalid and one hexostomid monogeneans, and one ca...

In the last few years, the study of environmental DNA (eDNA) has drawn attention for many reasons, including its advantages for monitoring and conservation purposes. So far, in aquatic environments, most of eDNA research has focused on the detection of single species using species-specific markers. Recently, species inventories based on the analysis of a single generalist marker targeting a lar...