Journal of the Ocean Science Foundation
Info
Bathygobius is a genus of small gobies, but they are not as well known as Eviota or Trimma gobies.
Bathygobius mero was determined based on 8 adult specimens, 26.3 - 36.0 mm SL, collected in eastern Bali, Indonesia.
In addition, there is photographic evidence of Bathygobius mero from Sumba, Indonesia, Cebu, Philippines, and Queensland, Australia.
Diagnostic characteristics include 19-21 (usually 20) pectoral fin rays, with the upper three being the upper three rays free of the membranous portion of the fin and each having two filiform tips, a mostly scaleless midline except for two or three scales in front of the first dorsal fin insertion, and 33 or 34 lateral scales.
The coloration of living gobies is overall pale greyish with a dense covering of reddish-brown freckles, a brown spot (about one-third the size of the pupil) at the uppermost part of the gill opening, and reddish-brown spots on the fins.
Some individuals (see Fig. 5 & 7 of the original description) have 6 - 8 diffuse white saddles or stripes, which are visible in smaller fish of less than about 20 mm SL.
The new species lives in association with the large barrel sponge (Xestospongia testudinaria), in contrast to other representatives of the genus, which are usually free-living bottom dwellers. It also lives at deeper depths (9-30 m, but usually below about 15 m) than most Bathygobius, which are mainly restricted to shallow waters below 10 m.
Distribution and habitat.
The new species is currently only known from four sites, including two in Indonesia: the type locality on Bali and a photographic record from Sumba by the second author. There are two further photographic records, one from the Gulf of Carpentaria, Queensland, Australia, submitted by Andrew Green, and another from Cebu, Philippines, which can be seen on a Japanese website of Cebu fishes.
All collected and photographed individuals were associated with barrel sponges (Xestospongia testudinaria).
The type specimens lived on a single sponge at a depth of 18 m. Numerous other individuals were also observed at this site, all associated with barrel sponges, with up to about 20 individuals on a single sponge, at depths of 9–30 m.
The goby inhabits the outer surface of the sponge rather than the hollow central cavity, occupying the deep, winding gullies between the longitudinal ridges and not being seen in the shallower gullies of the sponge.
This relationship is unique among the Bathygobius species, which generally live freely on sand or hard surfaces in the reef environment.
However, members of the gobiid genera Bryaninops, Phyllogobius, Lobulogobius, Luposicya and Pleurosicya form similar associations with sponges, sea whips, gorgonian fans, tunicates, algae and corals (hard and soft).
Another species, Pleurosicya labiata (Weber,
2013), also belongs to this group and is associated with large barrel sponges. Both this species and the new species associated with this sponge have a mottled appearance that blends well with the sponge.
Etymology. The new species is named mero in reference to the Indonesian Marine Education and Research Organization (MERO), Tulamben, Bali, for their generous support of this study.
Citation: Allen, G. R., Erdmann, M.V. & Ichida, N.K. (2024) A new sponge-dwelling goby (Gobiidae: Bathygobius)
from Indonesia, Philippines, and Australia. Journal of the Ocean Science Foundation, 41, 46–53.
doi: https://doi.org/10.5281/zenodo.14003729
urn:lsid:zoobank.org:pub:C755F083-C52C-4A9B-AFF8-C3117CA5D6EE
Bathygobius mero was determined based on 8 adult specimens, 26.3 - 36.0 mm SL, collected in eastern Bali, Indonesia.
In addition, there is photographic evidence of Bathygobius mero from Sumba, Indonesia, Cebu, Philippines, and Queensland, Australia.
Diagnostic characteristics include 19-21 (usually 20) pectoral fin rays, with the upper three being the upper three rays free of the membranous portion of the fin and each having two filiform tips, a mostly scaleless midline except for two or three scales in front of the first dorsal fin insertion, and 33 or 34 lateral scales.
The coloration of living gobies is overall pale greyish with a dense covering of reddish-brown freckles, a brown spot (about one-third the size of the pupil) at the uppermost part of the gill opening, and reddish-brown spots on the fins.
Some individuals (see Fig. 5 & 7 of the original description) have 6 - 8 diffuse white saddles or stripes, which are visible in smaller fish of less than about 20 mm SL.
The new species lives in association with the large barrel sponge (Xestospongia testudinaria), in contrast to other representatives of the genus, which are usually free-living bottom dwellers. It also lives at deeper depths (9-30 m, but usually below about 15 m) than most Bathygobius, which are mainly restricted to shallow waters below 10 m.
Distribution and habitat.
The new species is currently only known from four sites, including two in Indonesia: the type locality on Bali and a photographic record from Sumba by the second author. There are two further photographic records, one from the Gulf of Carpentaria, Queensland, Australia, submitted by Andrew Green, and another from Cebu, Philippines, which can be seen on a Japanese website of Cebu fishes.
All collected and photographed individuals were associated with barrel sponges (Xestospongia testudinaria).
The type specimens lived on a single sponge at a depth of 18 m. Numerous other individuals were also observed at this site, all associated with barrel sponges, with up to about 20 individuals on a single sponge, at depths of 9–30 m.
The goby inhabits the outer surface of the sponge rather than the hollow central cavity, occupying the deep, winding gullies between the longitudinal ridges and not being seen in the shallower gullies of the sponge.
This relationship is unique among the Bathygobius species, which generally live freely on sand or hard surfaces in the reef environment.
However, members of the gobiid genera Bryaninops, Phyllogobius, Lobulogobius, Luposicya and Pleurosicya form similar associations with sponges, sea whips, gorgonian fans, tunicates, algae and corals (hard and soft).
Another species, Pleurosicya labiata (Weber,
2013), also belongs to this group and is associated with large barrel sponges. Both this species and the new species associated with this sponge have a mottled appearance that blends well with the sponge.
Etymology. The new species is named mero in reference to the Indonesian Marine Education and Research Organization (MERO), Tulamben, Bali, for their generous support of this study.
Citation: Allen, G. R., Erdmann, M.V. & Ichida, N.K. (2024) A new sponge-dwelling goby (Gobiidae: Bathygobius)
from Indonesia, Philippines, and Australia. Journal of the Ocean Science Foundation, 41, 46–53.
doi: https://doi.org/10.5281/zenodo.14003729
urn:lsid:zoobank.org:pub:C755F083-C52C-4A9B-AFF8-C3117CA5D6EE
