Wednesday, July 10, 2024

[Ichthyology • 2024] Luciogobius opisthoproctus • A New Species of the Genus Luciogobius Gill, 1859 (Gobiiformes: Oxudercidae) from Taiwan


 Luciogobius opisthoproctus 
 Chen & Liao, 2024


Abstract
A new species, Luciogobius opisthoproctus sp. nov., is described based on 18 specimens collected from Daxi Creek (Yilan) and Babian Creek (Taitung) in Taiwan. The new species is characterized by having a yellowish body with scattered spots on the sides, a black blotch on the caudal fin, the absence of free pectoral-fin rays, and more than 40 vertebrae. The new species can be distinguished from congeners by the following combination of characters: AAA distance (anus to anal-fin origin) shorter than twice the body depth at anus, 4.2–7.2% of standard length (SL); pre-anus length 80.0–92.8% of pre-anal-fin length; snout length 39.7–62.7% of AAA distance; abdominal vertebrae 20–22; caudal vertebrae 20–22; first anal-fin pterygiophore usually inserted behind the second haemal spine.

Key words: Actinopterygii, amphidromous, earthworm goby, interstitial habitat, taxonomy, western Pacific

Fresh specimens of Luciogobius opisthoproctus sp. nov.
A holotype, ASIZP0081790, 25.4 mm SL, Daxi Creek, Yilan County, Taiwan B paratype, ASIZP0081793, 23.8 mm SL, Daxi Creek, Yilan County C paratype, NMMB-P39322, 21.4 mm SL, Daxi Creek, Yilan County, Taiwan.

Live  Luciogobius opisthoproctus sp. nov. NMMB-P39326, paratype, 27.5 mm SL, Daxi Creek, Yilan County, Taiwan.

 Luciogobius opisthoproctus sp. nov.
  New English name: Taiwan Earthworm Goby

Diagnosis: Luciogobius opisthoproctus sp. nov. is diagnosed by the following combination of characters: total vertebrae 41–43; free pectoral-fin rays absent; second dorsal-fin rays 9–12 (usually 11); anal-fin rays 11–14 (11 or 12); pectoral-fin rays 8–12 (10 or 11); pelvic-fin length more than 50% of pectoral-fin length; AAA distance 4.2–7.2% (mean 5.7%) of SL, 72.1–129.7% (mean 99.9%) of body depth at anus; snout length 39.7–62.7% (mean 52.8%) of AAA distance; pre-anus distance 80.0–92.8% (mean 88.6%) of pre-anal-fin length; and anterior-most pterygiophore of anal fin inserted behind the second haemal spine (Fig. 5).

Etymology: The specific name opisthoproctus is from the Greek words opisthe (behind) and proktos (anus), in allusion to the posteriorly positioned anus (shorter AAA distance).



 Kuan-Hsun Chen and Te-Yu Liao. 2024. A New Species of the Genus Luciogobius Gill, 1859 (Teleostei, Oxudercidae) from Taiwan. ZooKeys. 1206: 241-254. DOI: doi.org/10.3897/zookeys.1206.118757