Reproductive strategy of a small endemic cyprinid, the Yarqon bleak ( Acanthobrama telavivensis ), in a mediterranean-type stream

摘要: A mediterranean-type climate exists in five widely separated regions; the Mediterranean basin, parts of western North America, and southern Australia, southwestern South Africa central Chile. Streams these regions feature seasonal disturbances contrasting hydrology with high predictability timing flooding drying but low constancy. We would expect fish living streams to avoid scouring flow breed after cessation flood period. The aim present study was examine adaptation Yarqon bleak, Acanthobrama telavivensis, an endemic cyprinid coastal Israel, stream (mediterranean—written a small m, is used connection or ecological region distinguished from that geographical context, referring basin.) conditions. For we studied its reproductive strategy (age at maturity life span, gonad activity, oocyte maturation, spawning activity habitats, appearance juveniles), major costal (Yarqon). Our findings show bleak exhibits history traits attuned mediterranean-climate hydrologic regime. It breeds late winter early spring, window opportunity between flash floods habitat desiccation. Being multiple spawner allows compensate for potential loss part output due flows floods. ability spawn on different substrate-types enables it take advantage conditions pertain years. attains pre-adult size (ca. 33–42 mm) within first year, prior out most reaches, matures by beginning second year (males >41; females >42 mm). cost tactics short span (4–5 age groups). falls into category in-channel breeding but, unlike case suggested recruitment model, during period cessation, transitional time flows, rather than flow. Breeding this puts stages somewhat risk being washed away floods, gains them longer growth under favorable suggest additional positive tradeoff should be investigated: reduced competition 0 other later season. This model seems appropriate