taxonID	type	description	language	source
0E8E520FA6815EB6BDB9CFCAF43222F0.taxon	description	Figs 1, 2, 3, 4, 5, 6	en	Fujiwara, Kyoji, Motomura, Hiroyuki, Shinohara, Gento (2023): Opistognathus ctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan. ZooKeys 1179: 353-364, DOI: http://dx.doi.org/10.3897/zookeys.1179.109813, URL: http://dx.doi.org/10.3897/zookeys.1179.109813
0E8E520FA6815EB6BDB9CFCAF43222F0.taxon	diagnosis	Diagnosis. A species of Opistognathus distinguished from congeners by the following combination of characters: posterior end of upper jaw rigid, without flexible lamina; dorsal-fin rays XI, 16 - 18; anterior dorsal-fin spines very stout and straight, and their distal ends not transversely forked; anal-fin rays II, 17; gill rakers 6 or 7 + 13 or 14 = 20 or 21; vertebrae 10 + 22 = 32; longitudinal scale rows c. 40 - 50; lateral line terminating below 4 th- 6 th soft ray of dorsal fin; 4 th and 5 th mandibular pore positions usually included 2 and 6 - 7 pores, respectively; body scales absent anterior to vertical below 4 th or 5 th dorsal-fin spine; vomerine teeth 2; body reddish-brown with 3 or 4 longitudinal rows of c. 8 - 10 whitish blotches; cheek and opercle with five or six whitish blotches; snout, suborbital region, and both jaws without blotches or stripes; spinous dorsal fin with ocellus between 2 nd to 5 th spines; dorsal-fin soft-rayed portion with two reddish-orange stripes; pectoral-fin base with one or two whitish blotches; caudal fin uniformly faint orange or reddish-yellow.	en	Fujiwara, Kyoji, Motomura, Hiroyuki, Shinohara, Gento (2023): Opistognathus ctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan. ZooKeys 1179: 353-364, DOI: http://dx.doi.org/10.3897/zookeys.1179.109813, URL: http://dx.doi.org/10.3897/zookeys.1179.109813
0E8E520FA6815EB6BDB9CFCAF43222F0.taxon	description	Description. General appearance of type specimens as in Figs 1, 2 and 3. Lateral line system and osteological features of the holotype are given in Figs 4 and 5, respectively. Lateral line system and scale descriptions based on KAUM-I. 174226, 174227 (not available for NSMT-P 130174 due to poor specimen condition). Counts and measurements of type specimens are given in Table 1. Head and body. Body elongate, compressed anteriorly, progressively more compressed posteriorly. Anus situated just before anal-fin origin. Head cylindrical, its profile rounded. Eyes somewhat large, located dorsolaterally. Anterior nostril a short membranous tube with a tiny tentacle on posterior rim, when depressed not reaching posterior nostril; situated about mid-way between posterior nostril and dorsal margin of upper lip. Posterior nostril opening elliptical. Mouth terminal, obliquely inclined anterodorsally, forming angle of c. 20 ° with body axis. Anterior tip of upper jaw slightly before vertical through lower-jaw tip. Posterior margins of preopercle and opercle indistinct, covered with skin and generally rounded with slightly elongated flap on upper part, respectively. Gill opening wide, its uppermost point slightly below horizontal through dorsal margin of orbit in lateral view. Lateral line system. Cephalic sensory pores moderately developed, covering most of head except for lower part of cheek and area adjacent to dorsal-fin origin. Mandibular pore positions 1 and 2 each with a single similarly-sized pore; position 3 with a single pore (largest size of mandibular pores); positions 4 and 5 with 1 (only left side of KAUM-I. 174227) or 2 and 6 or 7 pores, respectively. Lateral-line pores moderate, mostly in single series above and below embedded lateral-line tubes. Lateral line ending below 4 th (KAUM-I. 174226) or 6 th (KAUM-I. 174226) soft rays of dorsal-fin rays. Scales. Scales mostly missing, scaled area and scale counts estimated from scale pockets. Lateral surface of body and belly scaled, except above and slightly below lateral line, area anterior to vertical below 4 th (KAUM-I. 174227) or 5 th (KAUM-I. 174226) dorsal-fin spine, pectoral-fin base, and chest. Head region and bases of vertical fins completely naked. Fins. Dorsal fin moderately low, its profile relatively uniform except for anterior part and slightly notched junction of spinous and segmented rays; 1 st dorsal-fin spine distinctly short, its base located between uppermost point of gill opening and posteriormost tip of flap on opercle; all dorsal rays branched distally. Anal fin of similar height to dorsal fin, its origin vertically level with base of 1 st (KAUM-I. 174226) or 2 nd (KAUM-I. 174227, NSMT-P 130174) dorsal-fin soft ray; last anal-fin ray close to caudal-fin base and vertically level with last dorsal-fin ray; all fin rays branched distally. Pelvic-fin origin anterior to vertical through dorsal-fin origin; first ray of pelvic fin robust, not tightly bound to second ray; membrane between first and second rays incised distally; second ray longest, innermost 3 rays branched. Pectoral-fin base below 2 nd and 3 rd dorsal-fin spine bases. Caudal fin rounded posteriorly. Osteological features. Nasal short, tube-like. Vomer rhombic, with two tiny conical teeth anteriorly. Lateral ethmoid somewhat broad, articulating with 1 st infraorbital and palatine ventrally. Palatine robust anteriorly, tapering posteriorly, without teeth. Infraorbitals relatively slender, comprising 5 elements, including dermosphenotic; 1 st infraorbital longest, 3 rd with suborbital shelf, 5 th (= dermosphenotic) firmly attached to sphenotic. Basisphenoid crescentic. Frontal tapering anteriorly, 6 large dorsal openings for sensory canal from anteriormost tip to lateral aspect. Left and right parietals separated by supraoccipital. Anterior and posterior tips of supraoccipital strongly pointed. Sphenotic not expanded. Supratemporals associated with parietal and pterotic. Premaxilla with a single row of conical teeth, except for posterior end. Maxilla long, posteriorly broadly expanded with slightly rounded corners. Supramaxilla small, on upper posterior end of maxilla. Dentary with a single row of conical teeth; 5 large ventral openings (including on posterior tip) from mandibular sensory canal. Anguloarticular large, its anterior projection fitting into dentary notch; coronoid process strongly pointed, directed anterodorsally. Retroarticular small, on ventroposterior corner of anguloarticular. Hyomandibular broadly attached to sphenotic and pterotic. Ectopterygoid and symplectic slender. Entopterygoid forming a large shelf. Metapterygoid and quadrate present but poorly resolved, Opercle with 2 strong and 1 weak ridge. Preopercle with 5 large openings from preopercular sensory canal. Subopercle small, its anterior tip pointed. Interopercle triangular, size similar to subopercle. Six long recurved branchiostegal rays. Posttemporal L-shaped, forked, dorsal limb articulating with epiotic, an opening on posterior corner. Supracleithrum rod-like. Cleithrum with a large dorsal blade, receiving supracleithrum. Dorsal postcleithrum rectangular, articulating with cleithrum and scapula. Ventral postcleithrum long, narrow. Scapula widely separated from coracoid. Pectoral-fin radials comprising 4 elements, lowermost distinctly largest. Supraneural bone absent. Anterior dorsal- and anal fin interdigitation patterns // 1 / 1 + 1 / 1 / and // 1 + 1 / 1 / 1 / 1 /, respectively.	en	Fujiwara, Kyoji, Motomura, Hiroyuki, Shinohara, Gento (2023): Opistognathus ctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan. ZooKeys 1179: 353-364, DOI: http://dx.doi.org/10.3897/zookeys.1179.109813, URL: http://dx.doi.org/10.3897/zookeys.1179.109813
0E8E520FA6815EB6BDB9CFCAF43222F0.taxon	distribution	Distribution and habitat. Currently known only from the Osumi and Ryukyu islands, southern Japan in depths of 35 - 57 m (Fig. 6). The Ryukyu specimen (NSMT-P 130174) was collected from a sandy gravel bottom.	en	Fujiwara, Kyoji, Motomura, Hiroyuki, Shinohara, Gento (2023): Opistognathus ctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan. ZooKeys 1179: 353-364, DOI: http://dx.doi.org/10.3897/zookeys.1179.109813, URL: http://dx.doi.org/10.3897/zookeys.1179.109813
0E8E520FA6815EB6BDB9CFCAF43222F0.taxon	etymology	Etymology. The specific name is a noun in apposition derived from the Greek diminutive κτενίον, meaning " a small comb ". It refers to the low gill raker numbers in the new species, one of the lowest recorded for Indo-Pacific species of Opistognathus (see below).	en	Fujiwara, Kyoji, Motomura, Hiroyuki, Shinohara, Gento (2023): Opistognathus ctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan. ZooKeys 1179: 353-364, DOI: http://dx.doi.org/10.3897/zookeys.1179.109813, URL: http://dx.doi.org/10.3897/zookeys.1179.109813
