An Efficient Technique for the Captive Breeding of an Endangered Freshwater Fish Salaria fluviatilis ( Pisces : Blenniidae ) , with a Description of Its Ontogeny Fátima

Salaria fluviatilis is one of the few freshwater members of the family Blenniidae and occurs around the Mediterranean Basin. This species is vulnerable or endangered in most countries where it occurs. Thus, information on its developmental biology and the establishment of methods for ex situ reproduction of highly endangered populations, to preserve them until natural habitats are restored, are much needed. A technique for the culture of this endangered species in controlled conditions is presented, together with the description of the full developmental sequence, from egg to adult. The use of the rotifer Brachionus calyciflorus at the onset of exogenous feeding proved to be an efficient way to allow larvae to reach the size when they can feed upon Artemia nauplii. Embryonic development lasted 12–14 d at 20–21 C. Newly hatched larvae measured 5.1 mm total length (TL). The mouth and anus were opened; the eyes were pigmented; there were almost no yolk; and the pectoral fins were small and unpigmented. Most larvae settled at 13.0–14.0 mm TL (27–31 d after hatching) and showed full juvenile pigmentation patterns at 27.0–28.0 mm TL (83 d after hatching). The larvae of this species showed agonistic behaviors once they began to settle. Salaria fluviatilis (Asso 1801) is a freshwater member of the blenniid family that lives in rivers and lakes in the Mediterranean Sea basin and also in Portugal (Oliveira et al. 1992; Crivelli 1996). Although there are many studies about the ecology of this species (e.g., Freeman et al. 1990; Côté et al. 1999; Vinyoles et al. 1999, 2002), there is little information about its developmental biology. For the Iberian Peninsula, Vinyoles and De Sostoa (2007) described the life-history traits of this species. Sexual maturity is attained during their first year of life and females spawn multiple times during the breeding season. The breeding period is from May/June to August (Vinyoles and De Sostoa 2007). The demersal eggs are individually attached to the underside of a rock, or other 1 Corresponding author. protected substratum, and formed single layered patches. They are guarded and aerated by the male until hatching. Typically, several females spawn in the same nest so that at a given time each male is guarding eggs at several developmental stages (Wickler 1957). S. fluviatilis is classified as vulnerable or endangered in the majority of the countries where it occurs (see Vinyoles and De Sostoa 2007). It is listed in the Appendix III of the Berne Convention, in the Appendix II of the Habitats Directive and is listed as Endangered in the Portuguese and the Spanish Vertebrate Red Data Books (SNPRCN 1992; Doadrio 2002), because of habitat loss, water pollution, the introduction of exotic species, and excessive water extraction (Elvira 1995; Collares-Pereira et al. 2000; Hernández et al. 2000). There is an urgent need to design and implement effective management and conservation measures to recover this endangered © Copyright by the World Aquaculture Society 2010