Gobiodon rivulatus (Rüppel, 1830)

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 : 173-174

Gobiodon rivulatus (Rüppel, 1830) : Rippled Coralgoby

Synonyms or described as: Gobius rivulatus Rüppel, 1830 , and Gobius coryphaenula, Valenciennes, 1837 .

Description: Gobiodon rivulatus is characterised by both adults and juveniles having narrow wavy bright blue lines running vertically along the entire length of the head and body ( Figure 25 ). There are two distinct base colour morphs recorded, a lighter and darker base body colouration. The lighter colouration is often a translucent green or blue colour with occasional orange/red shades apparent. The darker colouration is often a dark brown to grey colour with some green apparent.

Distribution: Gobiodon rivulatus is found throughout the whole known range of Gobiodon , including the Pacific Ocean, Indian Ocean and Red Sea (GBIF.Org, 2024).

Habitat: Gobiodon rivulatus is known to inhabit a wide range of Acropora corals, with the most frequently recorded species being digitate corals such as A. gemmifera , A. digitifera ( Dana, 1846) and A. secale ( Munday, Harold and Winterbottom, 1999; Froehlich et al., 2024). It has been suggested that the variation of the base colour could be associated with the occupation of a host coral, as Munday et al. (1999) stated that individuals observed on A. secale were typically darker and larger than those on A. gemmifera .

Status: The species is listed as ‘Least Concern’ by the IUCN Red List ( Larson, 2019i) .

Sociality: Gobiodon rivulatus is typically observed hosting corals in pairs or groups (mean group size: 2.59, SI: 0.33–0.65) ( Hing et al., 2018; Hing, 2019; Froehlich et al., 2024).

Genetics: Gobiodon rivulatus has no consistent sister species, but is frequently located within a clade alongside G. quinquestrigatus , G. spadix , G. oculolineatus , G. bilineatus , G. reticulatus and G. irregularis ( Harold et al., 2008; Duchene et al., 2013; Herler, Bogorodsky and Suzuki, 2013; Hing et al., 2019).

Figures

FIGURE 25. LEFT: Illustrations of Gobiodon rivulatus and the two colour variations observed, by C. Hildebrandt. RIGHT: Photograph of a light morph Gobiodon rivulatus by V. N. Peinemann in the Red Sea.