Yasuhikotakia modesta (Bleeker, 1864)

Conway, Kevin W., 2011, Osteology of the South Asian Genus Psilorhynchus McClelland, 1839 (Teleostei: Ostariophysi: Psilorhynchidae), with investigation of its phylogenetic relationships within the order Cypriniformes, Zoological Journal of the Linnean Society 163 (5), pp. 50-154 : 99-101

publication ID	https://doi.org/ 10.1111/j.1096-3642.2011.00698.x
persistent identifier	https://treatment.plazi.org/id/03B287ED-FFCF-3723-FF1F-13B584F8AC3F
treatment provided by	Valdenar
scientific name	Yasuhikotakia modesta
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Treatment

I. Yasuhikotakia modesta View in CoL J. Acanthocobitis cf. zonalternans

1 mm 1 mm

In members of the genus Psilorhynchus View in CoL , the families Gyrinocheilidae View in CoL and Catostomidae View in CoL , and in Gastromyzon cranbrooki View in CoL , the preopercular sensory canal does not connect with the otic sensory canal but instead connects with the infraorbital sensory canal, level with the dorsalmost tip of the preopercle ( Siebert, 1987; Figs 6 View Figure 6 , 26E–G View Figure 26 ). In other cypriniform fishes and in outgroup taxa the preopercular sensory canal connects with the otic sensory canal and remains separate from the infraorbital sensory canal. This character is inapplicable to taxa in which the preopercular and/or the infraorbital sensory canal are absent.

50. Interopercle: (0) anteriormost point directed anteriorly; (1) anteriormost point directed anteromedially towards ventral midline (CI = 1.00; RI = 1.00).

In members of the family Gyrinocheilidae the anteriormost point of the interopercle is roughly spoonshaped, and is directed anteromedially towards the ventral midline ( Fig. 27C, D View Figure 27 ). In other cypriniform fishes and in outgroup taxa the anteriormost point of the interopercle is roughly triangular in shape, and is directed anteriorly ( Figs 7, 26 View Figure 26 , 27A, B, E–H View Figure 27 , 28 View Figure 28 ).

51. Interopercular–preopercular articulation: (0) absent; (1) present (CI = 0.50; RI = 0.94).

In members of the genus Psilorhynchus and in the labeonine cyprinids the preopercle and interopercle articulate anteriorly via small, heavily ossified, peglike processes that exhibit a thick meniscus-like coating on their dorsal surface ( Figs 7 –9, 27B, C). When the lower jaw is extended the process of the interopercle glides past its counterpart on the preopercle. The function of this interopercular– preopercular articulation is presently unclear. In other cypriniform fishes and in out-group taxa the surfaces of the preopercle and interopercle are relatively flat, and do not articulate with each other ( Fig. 27A, D–F View Figure 27 , 28 View Figure 28 , 29 View Figure 29 ).

52. Anterodorsal head of opercle: (0) absent, or if present short; (1) greatly elongate (CI = 0.5; RI = 0.00).

In certain members of the Catostomidae the anterodorsal head of the opercle is greatly elongated, extending much further dorsally than its posterodorsalmost point ( Fig. 28B View Figure 28 ). In other cypriniform fishes the anterodorsal head of the opercle does not extend much further dorsally than its posterodorsalmost point, or is absent, as in outgroup taxa ( Figs 8 View Figure 8 , 27 View Figure 27 , 28A, C–H View Figure 28 , 29 View Figure 29 ).

53. Premaxilla ( Fink & Fink, 1981: character 37): (0) extending furthest dorsally at a point lateral to the dorsal midline; (1) extending furthest dorsally adjacent to the dorsal midline (CI = 0.5; RI = 0.80).

In all cypriniform fishes, except members of the Gyrinocheilidae , the premaxilla extends furthest dorsally adjacent to the dorsal midline ( Fink & Fink, 1981; Fig. 23A, B, D–G). In members of the family Gyrinocheilidae and in outgroup taxa the premaxilla extends furthest dorsally lateral to the midline (Fig. 23C).

54. Oral teeth ( Fink & Fink, 1981: character 42); (0) present; (1) absent (CI = 1.00; RI = 1.00).

Oral dentition is absent from the jaws of all cypriniform and gonorynchiform fishes ( Fink & Fink, 1981). Oral dentition is present in all remaining outgroup taxa.

55. Coronomeckelian ( Sawada, 1982: character 2): (0) present; (1) absent (CI = 1.00; RI = 1.00).

In members of the family Cobitidae the coronomeckelian is absent ( Sawada, 1982; Fig. 28G, H View Figure 28 ). In other cypriniform fishes and in outgroup taxa the coronomeckelian is present ( Figs 8 View Figure 8 , 27 View Figure 27 , 28A–F View Figure 28 , 29 View Figure 29 ).

56. Angulararticular: (0) similar in width to the posteriormost point of the dentary in ventral view, not extended laterally as a sharp point; (1) much wider than the posteriormost point of the dentary in ventral view, extending laterally as a sharp point (CI = 1.00; RI = 1.00).

In the gastromyzontin balitorids Gastromyzon cranbrooki and Annamia normani , the angulararticular and retroarticular portion of the lower jaw is much wider than the posteriomost point of the dentary, and extends laterally as a sharp point ( Fig. 29C, D View Figure 29 ). In other cypriniform fishes and in outgroup taxa the angulararticular and retroarticular portion of the lower jaw is similar in width to the posteriormost point of the dentary ( Figs 4 View Figure 4 , 8 View Figure 8 , 27 View Figure 27 , 28 View Figure 28 , 29A, B View Figure 29 ).

57. Maxilla: (0) without large spine-like process overlapping dorsal surface of premaxillae; (1) with large spine-like process overlapping dorsal surface of premaxillae (CI = 1.00; RI = 1.00).

In the gastromyzontin balitorids Gastromyzon cranbrooki and Annamia normani the maxilla exhibits a pronounced spine-like process on its lateral face that extends ventrad and overlaps the adjacent dorsal edge of the premaxilla ( Fig. 29C, D View Figure 29 ). In other