| Summary: | 3rd Workshop on Gonadal Histology of Fishes, New Orleans, Louisiana, 11-12 July 2006 Fishes all over the world exhibit great diversity in reproductive strategies and associated traits (Helfman et al., 1997). This includes breeding mode, maturation and spawning pattern, fecundity, number of spawning occasions and partners, gender role, spawning habitat and season, etc. Many common marine, anadromous and catadromous fish species of commercial importance in the North Atlantic and North Pacific are iteroparous, i.e., can breed more than once; they are gonochoristic, i.e., separate sexes without distinctive sexual dimorphism, exhibit external fertilization and provide no parental care, e.g. gadoids, clupeids and flatfishes. However, there are many exceptions e.g., Pacific salmonids (Oncorhynchus spp.) and Lampreys (Petromyzontiformes) are semelparous, i.e., they spawn once and die. Fishes of the genus Sebastes (Atlantic redfishes and Pacific rockfishes) and some elasmobranchs are viviparous, i.e., embryos develop inside the ovary with internal fertilization of eggs. Viviparity in Sebastes is lecithotrophic, which means that larvae absorb nutrients from the accumulated yolk in the egg (formerly known as ovoviviparity). However, two Pacific Sebastes species (S. melanops and S. schlegeli), females seem at least partially to provide food for the embryos during their develoment, i.e., their viviparity is matrotrophic. Also a few hermaproditic species both sequential and synchronous are fished, but mainly in the recreational fishery, such as grouper, seabass and wrass. Their reproductive pattern includes sex-change and sex-reversion No
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