Territorial defence by the Brazilian damselStegastes fuscus(Teleostei: Pomacentridae)

Abstract

Territorial defence by Brazilian damselfish Stegastes fuscus was studied in north-east Brazil through underwater observations. The fish mostly fed on Gellidium sp. and strongly defended a territory with a mean size of 2 m 2 (range 1Á27-3Á07 m 2 ); its mean AE S.D. feeding rate was 8Á73 AE 2Á44 bites min À1 . Stegastes fuscus responded similarly to all intruding fish species, with aggressive behaviour becoming more pronounced only with an increase in the number of fishes in the sampled area. Analysis of attacks elicited by different fish species placed within S. fuscus' territory, however, showed that it launched more attacks on conspecifics than on other fishes.

Habitat use, feeding and territorial behavior of a Brazilian endemic damselfish Stegastes rocasensis (Actinopterygii: Pomacentridae)

“…However, while the invertebrates constituted about 30% of S. fuscus' diet (Ferreira et al 1998), it represented only 1% in S. rocasensis' diet. Conversely, Osório et al (2006) studying S. fuscus' diet in a Brazilian Northeastern reef noted that this species fed exclusively on algae. These results highlighted that Stegastes spp.…”

“…Species recorded within the territory were grouped according to trophic categories well-established in the literature (Randall 1967;Hobson 1975;Ferreira et al 2004): carnivores, mobile invertivores, omnivores, piscivores, planktivores, roving herbivores, sessile invertivores and territorial herbivores). Standard ago- nistic behaviors were categorized as lateral display, chase and bite, following Osório et al (2006).…”

Non-random reef use by fishes at two dominant zones in a tropical, algal-dominated coastal reef

“…On the other hand, territorial herbivores rely on specific substratum cover and high structural complexity, being highly dependent upon availability of both preferred food and shelter (Sale and Douglas 1984;Tolimieri 1998). Both juvenile and adult S. fuscus were more abundant on turf algae-dominated substrate, which they feed on (Osório et al 2006), and in areas with high quantities of holes, which they use as shelter (Ferreira et al 2001). …”

Morphological and genetic barcoding study confirming the first Stegastes variabilis (Castelnau, 1855) report in the Mediterranean Sea

“…The occurrence of S. variabilis in the Mediterranean Sea must be closely traced, as the damselfish of the genus Stegastes are considered to be among the most aggressive and highly territorial benthic feeders (Letourneur et al, 1997;Santangelo et al, 2002;Osório et al, 2006;Hutchings et al, 2008;Steele et al, 2010), and show to have significant impact on coral community structure and algal assemblages (Gobler et al, 2006), increasing the algal biomass and productivity of reef systems (Hinds & Ballantine, 1987;Ferreira et al, 1998;Ceccarelli, 2007), and thus have a potential of altering the ecosystems which they inhabit. …”