Sunday, January 31, 2021

[Ichthyology • 2020] Egglestonichthys fulmen • A New Species of Egglestonichthys (Gobiiformes, Gobiidae) from Okinawa Island, Japan


Egglestonichthys fulmen 
Fujiwara, Suzuki & Motomura, 2020


Abstract
Egglestonichthys fulmen sp. nov. (Teleostei: Gobiidae) is described on the basis of a single specimen (21.7 mm in standard length) collected from 250 m depth off Okinawa Island, Ryukyu Islands, Japan. The new species is characterized by the following combination of characters: anal-fin rays I, 9; pectoral-fin rays 17, lower rays not free from membrane; longitudinal scale series 25; transverse scales 8; pre-dorsal-fin scale rows 8; cheek and opercle naked; pelvic frenum absent; caudal fin lanceolate, its length 32.2% of SL; interorbital width very narrow, 1.2% of HL (much narrower than pupil diameter); no spicules or odontoid processes on outer surface of gill arches; and body whitish, upper half with broken zigzag pattern of bright yellow patches and associated scattered black melanophores in fresh specimens (melanophores retained in preserved specimens). Several characters, including pectoral-fin ray count, interorbital width, and coloration uniquely distinguish the new species from congeners.

Keywords: Deepwater, description, morphology, Ryukyu Islands, taxonomy


Figure 1. Holotype of Egglestonichthys fulmen sp. nov., OMNH-P 43993, 21.7 mm SL, Okinawa Island, Ryukyu Islands, Japan
A fresh coloration B preserved coloration C radiograph.


Figure 2. Sketches of head region of Egglestonichthys fulmen sp. nov. based on OMNH-P 43993, holotype, 21.7 mm SL. Note that sensory papillae have been abraded during capture
A dorsal view B lateral view C ventral view.
AN and PN indicate anterior and posterior nostrils, respectively. Arrowheads indicate anteroventral end of gill opening. Scale bar: 1 mm.

Egglestonichthys fulmen sp. nov.
  New English name: Eggleston’s Lightning Goby 
New standard Japanese name: Raitei-haze
  
Diagnosis: A species of Egglestonichthys (Fig. 1) with the following combination of characters: anal-fin rays I, 9; pectoral-fin rays 17, lower rays connected by membrane; longitudinal series scales 25; transverse scales 8; pre-dorsal-fin scale rows 8; cheek and opercle naked (Fig. 2B); pelvic frenum absent; caudal fin lanceolate, its length 32.2% of SL; interorbital width very narrow, 1.2% of HL (much narrower than pupil diameter) (Fig. 2A); no spicules or odontoid processes on outer surface of gill arches; and body whitish, upper half with broken zigzag pattern of bright yellow patches and associated scattered black melanophores in fresh specimens (melanophores retained in preserved specimens) (Fig. 1A, B).

Distribution: Currently recorded only from Okinawa Island, Ryukyu Islands, Japan, from a depth of 250 m.

Etymology: The specific name “fulmen” is derived from Latin, meaning “lightning”, in reference to the bright yellow zigzag pattern on the upper part of the body.


 Kyoji Fujiwara, Toshiyuki Suzuki and Hiroyuki Motomura. 2020. A New Species of Egglestonichthys (Teleostei, Gobiiformes, Gobiidae) from Okinawa Island, Japan. ZooKeys. 1006: 91-98. DOI: 10.3897/zookeys.1006.58874