Gobiodon erythrospilus Bleeker 1875

Gobiodon erythrospilus Bleeker 1875 View in CoL : Red Spotted Coralgoby

Synonyms or described as: Gobius douglasi Saville — Kent, 1893, and Gobiodon histrio erythrospilus form ( Munday, Harold and Winterbottom, 1999).

Description:. Gobiodon erythrospilus is characterised by lime green/turquoise body colouration with four to five broad red bands vertically on the facial area and a body patterned with irregular spots forming loose highly broken lines or dot series down the entirety of the flank ( Figure 13 View FIGURE 13 ). There is no black spot on the upper opercular margin, a distinguishing feature to G. histrio which does have this marking. Fins are often a lighter variation of the body colour or more yellow in colouration, with a fine pale black border (Suzuki et al., 1995; Munday et al., 1999). The total body length can often exceed 50mm ( Munday, Harold and Winterbottom, 1999). Once considered to be a variation or subspecies of G. histrio ( Munday, Harold and Winterbottom, 1999) , G. erythrospilus has since been recognised as a valid species through both genetic and morphometric methods ( Harold et al., 2008; Duchene et al., 2013; Shibukawa, Suzuki and Aizawa, 2013).

Distribution: The geographic variation in abundance of G. erythrospilus is known to vary relative to that of G. histrio with changes in latitude ( Munday, Harold and Winterbottom, 1999). Gobiodon erythrospilus is more frequently recorded in the southern areas of the Great Barrier Reef, such as One Tree Island and Heron Island, whilst G. histrio is more frequent at lower latitudes, such as Kimbe Bay in Papua New Guinea ( Munday et al., 1999; Hildebrandt, pers obs.). In the middle of the two extremes, e.g. Lizard Island in the northern Great Barrier Reef, the frequency of observation is roughly equal. The trend has not been reported in the Northern Hemisphere.

Habitat: Gobiodon erythrospilus is found in the corymbose and caespitose corals of the genus Acropora , most notably A. nasuta , A. valida , A. cerealis , A. loripes , A. millepora , A. spathulata ( Brook, 1891) , and occasionally A. tenuis ( Munday, Harold and Winterbottom, 1999; Pereira and Munday, 2016; Froehlich et al., 2023). There are multiple species of Gobiodon that inhabit these corals at high frequencies, however it has been observed that different gobies inhabit these preferred corals in different reef locations ( Munday and Wilson, 1997). Gobiodon erythrospilus is more commonly found on the reef slopes, lagoons and protected areas, whilst G. axillaris who prefers the same corals is often found in the less protected areas of the reef ( Munday and Wilson, 1997).

Status: The species is recorded as ‘Vulnerable’ by the IUCN ( Larson, 2020f).

Sociality: Gobiodon erythrospilus sits in the middle of the sociality spectrum for the genus, and is often observed in pairs (mean group size: 1.86, SI: 0.33–0.42) ( Hing et al., 2018; Hing, 2019; Froehlich et al., 2024).

Genetics: Gobiodon erythrospilus is frequently adjacent to G. histrio in phylogenetic analyses ( Harold et al., 2008; Duchene et al., 2013; Herler, Bogorodsky and Suzuki, 2013; Hing et al., 2019). This clade is known to include other species with a deeper and more compressed body shape and varying degrees of colour patterns, such as G. histrio , G. fuscoruber , G. axillaris , G. ater and G. fulvus ( Harold et al., 2008; Duchene et al., 2013; Herler, Bogorodsky and Suzuki, 2013; Hing et al., 2019). The clade stays relatively stable despite usage of different genetic markers.