Spatial and temporal patterns of abundance of coral reef gobies (Teleostei: Gobiidae)

Abstract

This study investigated the spatial and temporal patterns of abundance of four substratumassociated species of Gobiidae on a heterogeneous reef flat comprised of four distinct habitat zones, and examined microhabitat use within each zone. Asterropteryx semipunctatus had the widest distribution and was the most abundant species in each habitat zone, followed by Amblygobius bynoensis, Valenciennea muralis and Amblygobius phalaena. Significant temporal and spatial differences in mean density were evident. The highest density of A. semipunctatus (312 individuals 10 m -2 ) was recorded in a habitat zone dominated by algal-covered rubble, whereas A. bynoensis and V. muralis were most abundant (mean summer density 5Á5-5Á8 individuals 10 m -2 ) in habitats containing both sand and hard substrata. In contrast, A. phalaena was uncommon (mean density 0Á4 individuals 10 m -2 ) in all four habitat zones. Significant seasonal differences in abundance were due to the large influx of recruits in summer. Ontogenetic shifts in habitat use were not evident at either the macrohabitat (i.e. among habitat zones) or microhabitat scale (i.e. substratum use within zones). At the microhabitat scale, V. muralis consistently exhibited a strong positive association with sand and was rarely associated with hard substrata. In contrast, the two Amblygobius species were commonly associated with both sand and hard substrata, but patterns of microhabitat use differed among habitat zones. Substratum composition at the microhabitat scale may influence spatial patterns of abundance at larger spatial scales by providing essential resources and, or influencing carrying capacity and predation risk.

Habitat segregation between two congeneric and introduced goby species

“…CB (cross-band type) is a result of interspecific competition (Sone et al 2001, Sone et al 2006. Alternatively, the two goby species might display differences in habitat use that could lead to selective habitat segregation (Gill & Potter 1993, Hernaman & Probert 2008, Horinouchi 2008, as observed for Acentrogobius sp. 1 and A. sp.…”

“…As substrata-associated species, most goby species show eschweizerbart_XXX limited capacity for quick and/or long distance swimming after they settle in the benthos and habitat use has substantial effects on access to trophic resources and individual performances (Hayden & Miner 2009). Several sympatric goby species have been found to show spatial segregation in use of microhabitats that differ in water flows (Sone et al 2006), water depths (Horinouchi 2008), aquatic vegetation (Hernaman & Probert 2008), types of substrata (Hernaman & Probert 2008, Horinouchi 2008, salinities and prey abundances (Gill & Potter 1993). However, most of these studies were conducted within the native ranges and not much is known about the habitat segregation once the species have been introduced into new environments (Keller & Taylor 2008).…”

“…Habitat is arguably the most important dimension that can promote resource partitioning and has often been implicated as a primary mechanism for coexistence among sympatric species with similar ecological functions (Hernaman & Probert 2008, Hesselschwerdt et al 2008, Amundsen et al 2010. Habitat segregation has been widely observed in fishes including closely related species (Sone et al 2006, Horinouchi 2008, Hernaman & Probert 2008, different age and size classes (Johnsona et al 2011), or polymorphic populations (Kahilainen et al 2004). As substrata-associated species, most goby species show eschweizerbart_XXX limited capacity for quick and/or long distance swimming after they settle in the benthos and habitat use has substantial effects on access to trophic resources and individual performances (Hayden & Miner 2009).…”

The ecology, behaviour and physiology of fishes on coral reef flats, and the potential impacts of climate change

“…Furthermore, larger individuals (heavier than the mean mass of 0·18 g) were more common in exposed, wave‐swept reef zones and microhabitat availability was important in areas with low wave energy (Depczynski & Bellwood, ). Substratum composition and microhabitat availability were also identified as critical drivers of abundance patterns of gobies across a heterogeneous reef flat comprising four habitats around Orpheus Island, Great Barrier Reef (Hernaman & Probert, ). Cryptobenthic fishes are the major resident component of fish assemblages on sandy areas that comprise significant areas of some reef flats.…”

Cryptobenthic fish assemblages across the coral reef−seagrass continuum in SE Sulawesi, Indonesia

“…Cryptobenthic fishes occur in high diversity in coral reef systems (Ackerman & Bellwood 2003, Depczynski & Bellwood 2003), yet little work has examined their assemblage structure along the continuum between the reef crest and seagrass beds. When studies have been extended to adjacent seagrass beds, they have been limited to a few targeted species (Hernaman & Probert 2008).…”