Pareuchiloglanis salicesbarba, Dao & Li & Yang & Zhou, 2020

Dao, Wei, Li, Xu, Yang, Hong-Fu & Zhou, Wei, 2020, Pareuchiloglanis (Teleostei: Sisoridae) from the Pearl River, China with description of three new species, Journal of Fish Biology 96 (1), pp. 23-36 : 32-33

3.4 | Pareuchiloglanis salicesbarba sp. nov.,

Figure 3d

3.4.1 | Holotype

SWFC 0705002, 135.8 mm L S; China: Yunnan Prov.: Quqing Pref.: Xuanwei Co.: Yangliu Town : Kedu-he (26 37 0 34.35 00 N, 104 16 0 27.57 00 E); collected by F.L. Li, 5 May 2007 .

3.4.2 | Paratypes

SWFC 0705001, 0705003 – 0705038, 0705040, 38 ex; 63.8 – 126.4 mm L S; the other data is the same as the holotype .

3.4.3 | Diagnosis

Pareuchiloganis posteranalis sp. nov. is distinguished from the congeners of the large-gill-opening group with long caudal peduncle by the following combination of characters (Table 1): anal-fin ray i, 3½ (v. i, 4½ in P. longicauda ); tip of the maxillary barbel pointed and only reaching the lower corner of the gill opening ( v. extending beyond the lower corner of the gill opening in P. arcuatum sp. nov and P. longicauda ); anal-fin origin located c. midpoint between the distance from pelvic-fin insertion to caudal-fin base (v. at about 2/5 of the distance between pelvic-fin insertion and caudal-fin base in P. arcuatum sp. nov.); the adipose-fin origin located at 66% of the distance between pelvic-fin insertion and anal-fin origin ( v. about 3/4 of distance between pelvic-fin insertion and anal-fin origin in P. longicauda and P. arcuatum sp. nov.); the length of dorsal-fin base shorter than the longest branched dorsal-fin ray ( v. longer in P. longicauda ); caudal-peduncle depth 18.3 – 23.0% of caudal-peduncle length (v. 14.1 – 17.8% in P. arcuatum sp. nov., 26.2 – 26.3% in P. longicauda and 27.2 – 31.3% in P. posteranalis sp. nov.).

3.4.4 | Description

Morphometric and meristic data are shown in Tables 1 and 2. Dorsal-fin rays i, 5½; anal-fin rays i, 3½; pectoral-fin rays i, 14 – 16; pelvic-fin rays i, 5 – 6; branched caudal-fin rays 6 + 7; vertebra 21 + 16 = 37 (n = 1), 22 + 16 = 38 (n = 2).

Mouth wide, inferior, transverse. Anterior margin of premaxillary tooth patches exposed when mouth closed. Oral teeth coniform, embedded in skin, only tips exposed, in irregular rows. Premaxillary tooth patches broad, appear joined, with median indentation, sides not extending posteriorly. Gill-opening extending to the base of first pectoral-fin element. Post-labial groove interrupted, ending at base of inner mandibular barbel. Lower lip connected to base of maxillary barbel by skin flap, without sulcus between them.

Head depressed, rostral margin rounded when viewed dorsally. Ventral surface of the head and abdominal region moderately broad and straight. Dorsal profile rising gradually from snout tip to dorsal-fin origin, then sloping slowly ventrally to caudal-peduncle base. The caudal-peduncle slightly compressed. Oral region and anterior part of abdomen with dense papillae, density gradually decreasing posteriorly. Eye small, almost round, subcutaneous, located on dorsal surface of head. Eye closer to dorsal-most extremity of gill opening than to tip of snout. Barbels flattened, in four pairs. Nasal barbel with small flap of thin skin fringing posterior margin, not reaching anterior margin of orbital. Maxillary barbel with thin flap of skin fringing posterior margin, tip pointed, elongating as a whisker shape and only reaching the lower corner of the gill opening. Origin of inner mandibular barbel distant from midline. Outer mandibular barbel originating posterolateral of inner mandibular barbel, not near pectoral-fin origin.

Dorsal-fin origin located at about the anterior 1/3 of the standard length (predorsal length 29.9 – 33.3% of L S), without spine, outer margin straight; tip of dorsal-fin rays extending beyond vertical through pelvic-fin insertion when depressed. Adipose-fin base longer, its length 43.4 – 48.3% of postdorsal distance but shorter than predorsal length; its margin almost straight and adipose-fin base deeply incised posteriorly. Anal-fin origin located at midpoint between the pelvic-fin insertion and the caudal-fin base. Pectoral and pelvic fins enlarged, with broadly rounded margins; the first element on each broadened, with regular striae on ventral surface. Pectoral fin not reaching pelvic-fin origin. Pelvic fin extending beyond anus. Anus located at anterior about 1/3 of the distance between the pelvic-fin insertion and the anal-fin origin, near pelvic-fin insertion. Caudal fin truncate; skin smooth; lateral line complete and midlateral.

3.4.5 | Coloration in life

Body green-yellow on dorsal surface, milk-white on venter. Pectoral and pelvic fins yellow-brown, with light yellow distal margins. Pair of light yellow spots on posttemporal region. A yellow papilionaceous patch at dorsal-fin origin, a yellow triangular or quadrate patch at end of dorsal-fin base. Adipose fin with light yellow distal margins and a yellow stripe on its origin. Patch on dorsal caudal-fin base connecting with patch at end of adipose-fin base.Caudal fin gray-black with light yellow distal margin (Figure 6).

3.4.6 | Distribution

Only known from the Beipan-jiang, a branch of the Hongshui-he, Xi-jiang in the Pearl River drainage (Figure 4).

3.4.7 | Habitat and ecology

Pareuchiloganis salicesbarba sp. nov. feeds on aquatic insects. Specimens were exclusively captured in rocky riffles where the width of the riverbed is narrow and the water is shallow, about 8 – 15 m wide and not more than 1 m deep. The water is clear and swift-flowing. The substrate is primarily cobbles and pebbles (Figure 5c).

3.4.8 | Etymology

From the Latin salices-, meaning Salix , a genus of plant; and -barba, meaning barbel. Alluding to the feature that their maxillary barbels look like the tip of a Salix leaf. Used as a noun.