Breeding ecology and nest aggregations in a population of Salaria pavo (Pisces: Blenniidae) in an area where nest sites are very scarce

Abstract

In this paper we present data on the breeding ecology and patterns of nest aggregation in a population ofSalaria pavo (Pisces: Blenniidae), in an area where hard substrates are very scarce. The study site was at Ria Formosa, an extensive littoral lagoon on the south coast of Portugal. The only hard materials available are bricks, tiles, stones and debris that clam culturists use to delimit their fields. The males of S. pavo establish nests intertidally in the holes of the bricks where they guard the eggs. Data were collected at low tide inspections of these artificial ridges and underwater behavioural observations during high tide. The main results are: (i) the same male can establish sequentially more than one nest in the same breeding season; the number of males that stay within the bricks increases before the start of the breeding season and declines towards its end; (ii) there is a large excess of mature males that do not establish nests and they are significantly smaller than the nesting males, suggesting very strong competition for nest sites; (iii) the nests of several males occur in adjacent holes of the same brick, sometimes being entirely surrounded by other nests. Thus, in this population, there is virtually no defended territory around the nest, a situation not known for other blenniid species. This pattern of nest aggregation implies both strong competition among males and reduction of aggression between neighbour parental fishes. This can be explained by the extreme scarcity and spatial distribution of available nest sites.

Patterns of shelter usage and social aggregation by the vocal Lusitanian toadfish

“…These results also conform to the pattern of shelter occupation in the intertidal zone in other teleosts with male parental care such as gobies or blennies of temperate coasts (e.g. Zander 1990;Almada et al 1994). Males of these Wshes migrate to the intertidal to defend nests that they use to receive spawns from multiple females and leave the area when the breeding season is over.…”

“…Males of these Wshes migrate to the intertidal to defend nests that they use to receive spawns from multiple females and leave the area when the breeding season is over. Almada et al (1994) suggested that in temperate areas, environmental pressures (e.g., caused by tides, temperature, food availability and other factors) permit only seasonal utilization of nearshore, shallow water habitats. Hence, many species are found to migrate to deeper waters to search for suitable habitat and for better feeding sites.…”

“…In many temperate species, individuals move from overwintering deeper water to more littoral habitats where they breed (Almada et al 1994). Even in true rocky intertidal resident species, there are often movements to places where structures favourable to serve as nest holes are available.…”

Birth date predicts alternative life‐history pathways in a fish with sequential reproductive tactics

“…The population studied inhabits the Culatra island (36°59 0 N, 7°51 0 W), Parque Natural da Ria Formosa (Ramsar RS212), Algarve, Portugal (for a detailed description of the habitat, see Almada et al 1994). In this region, clam culturists use bricks and other debris to delimit their fields, and S. pavo males use these structures as shelters and nest sites.…”

Seasonal cell differentiation and olfactory potency of secretions by the anal glands of male peacock blenny Salaria Pavo

“…Salaria pavo breeds from May until September in Ria Formosa (south Portugal, Algarve, 36°599 N; 7°519 W), an extensive littoral lagoon where males establish nests in the holes of bricks that clam culturists use to delimit their fields (Almada et al, 1994). Male blennies were captured inside these bricks at low tide during pre-spawning (13 males in January, mean AE S.D., standard length, L S , ¼ 103 Á 2 AE 5 Á 5 mm; mass, M, ¼ 15 Á 6 AE 3 Á 4 g), spawning (14 males in June to July, L S ¼ 111 Á 4 AE 10 Á 5 mm; M ¼ 21 Á 9 AE 6 Á 9 g) and postspawning periods (three males in October, L S ¼ 114 Á 0 AE 5 Á 6 mm; M ¼ 23 Á 2 AE 1 Á 6 g).…”