Gobiodon brochus Harold & Winterbottom, 1999

Gobiodon brochus Harold & Winterbottom, 1999 View in CoL : Rasp Coralgoby

Synonyms or described as: No recorded synonyms.

Description: The body colouration of Gobiodon brochus is often grey or beige with shades of green, yellow, or brown with a distinctive oblique pale area on the cheek ( Figure 9 View FIGURE 9 ). This pale area is bordered by two darker lines that extend from above and behind the eye. The lower lip of this species is recurved, giving it a distinctive downturned mouth. Specimens from the Great Barrier Reef, Fiji, New Caledonia and Tonga were believed to have been misidentified as the Indian Ocean species Gobiodon micropus (Günther, 1861) , however these specimens were distinctly different from those previously identified as G. micropus ( Harold and Winterbottom, 1999) . The main diagnostic features between the two species is that in G. brochus has a dentigerous pad anterior of the dentary symphysis giving it a unique jaw morphology, and a lower number of branched dorsal fin rays ( 10–12 in G. brochus and 12–13 in G. micropus ) and branched anal rays ( 9–10 in G. brochus and 11 in G. micropus ) ( Harold and Winterbottom, 1999).

Distribution: Gobiodon brochus has been recorded throughout the GBR, PNG and northern Pacific Ocean ( Munday, Harold and Winterbottom, 1999; GBIF.Org, 2024).

Habitat: The most frequently observed host coral for this species is A. loripes ( Harold and Winterbottom, 1999; Munday, Harold and Winterbottom, 1999), but the species has also been recorded occupying A. tenuis , A elseyi ( Brook, 1892) and larger individuals in A. nasuta (Patton, 1994; Munday et al., 1999). The occupation of these host corals suggests they will host numerous different coral growth forms.

Status: The IUCN Red List have described the population as ‘Near Threatened’ as of 2018 ( Larson, 2020d).

Sociality: Gobiodon brochus is generally seen occupying corals in pairs, occasionally alone or with a juvenile (mean group size: 2.0, SI: 0.33–0.36) ( Hing et al., 2018; Hing, 2019; Froehlich et al., 2024).

Genetics: Gobiodon brochus has been placed in a clade with G. aoyagii , G. bicalvolineatus and G. cobenjaminsis ( Duchene et al., 2013) . When the latter two species were not included in the analysis, the clade displayed only G. brochus and G. aoyagii ( Hing et al., 2019) . It should be noted that when only the 12S and 16S rRNA mitochondrial markers were used, G. brochus appeared as an early divergence from the clade containing G. quinquestrigatus and G. rivulatus ( Herler, Bogorodsky and Suzuki, 2013) .