Gobiodon spadix Sato and Motomura, 2024

Hildebrandt, Courtney A., Froehlich, Catheline Y. M., Klanten, O. Selma & Wong, Marian Y. L., 2025, Goby spotting: An updated guide to coral gobies (Genus: Gobiodon) in the Indo-Pacific Region, Zootaxa 5723 (2), pp. 151-188 : 174-175

Gobiodon spadix Sato and Motomura, 2024 : Akane or Tomato Coralgoby and previously recorded as Gobiodon sp. D

Synonyms or described as: Gobiodon sp. D ( Munday, Harold and Winterbottom, 1999).

Description: Gobiodon spadix does share characteristics with G. quinquestrigatus but has numerous distinguishing features. The base colouration of this species is red, with the fins being significantly darker than the body ( Figure 26 ). Pale blue lines adorn the facial region, though are not as prominent as those seen in G. quinquestrigatus and G. rivulatus . In the past this species has occasionally been recorded as G. quinquestrigatus , but genetic and morphological differences have been recognised over the years ( Munday, Harold and Winterbottom, 1999; Harold et al., 2008), designating the species the holding name of Gobiodon sp. D ( Munday, Harold and Winterbottom, 1999), followed by the description as G. spadix ( Sato and Motomura, 2024) .

Distribution: Gobiodon spadix has been recorded throughout the western Pacific Ocean, from Japan in the north to the southern GBR. Similar appearing individuals have been recorded in the Maldives in the central Indian Ocean, however they appear genetically distinct despite similar morphology ( Herler, Bogorodsky and Suzuki, 2013; Hildebrandt et al., 2024; Sato and Motomura, 2024).

Habitat: It has primarily been observed occupying the branching coral species A. divaricata ( Dana, 1846) , A japonica, Veron, 2000 , and A. solitaryensis, Veron and Wallace, 1984 , according to Munday, Harold and Winterbottom, 1999; Hildebrandt et al., 2024, and Sato and Motomura, 2024.

Status: Unfortunately, due to the species recent description, no IUCN population assessment has been made for this species.

Sociality: Whilst the species was observed in Hing et al. (2018), unfortunately there was low abundance of the species at the study site, resulting in insufficient group data to formulate an average group size and sociality index for this species ( Hing et al., 2018). However, the species has been observed in both pairs and groups (Froehlich and Hildebrandt, pers. obs.).

Genetics: Gobiodon spadix has appeared in a number of genetic analyses over the last few decades under the holding name of G. sp. D ( Harold et al., 2008; Duchene et al., 2013; Herler, Bogorodsky and Suzuki, 2013; Hing et al., 2019). Gobiodon spadix is consistently paired with the sister species G. quinquestrigatus ( Harold et al., 2008; Duchene et al., 2013; Herler, Bogorodsky and Suzuki, 2013; Hing et al., 2019). Across all conducted analyses, the clade appears to contain G. spadix , G. quinquestrigatus , G. bilineatus , G. oculolineatus G. rivulatus , G. reticulatus and G. irregularis ( Herler, Bogorodsky and Suzuki, 2013) .

Figures

FIGURE 26. LEFT: Illustration of Gobiodon spadix by C. Hildebrandt. RIGHT: Photograph of a collected Gobiodon spadix by C. Froehlich and C. Hildebrandt at One Tree Island, GBR.