Vibilia australis Stebbing, 1888

64. Vibilia australis Stebbing, 1888 View in CoL

ljẅḵșêăNjẹ (ṵÿ)** ( Figs. 9 View Fig , 10 View Fig )

Vibilia australis Stebbing 1888: 1287 View in CoL , pl. 149. - Shih & Chen 1995: 49, fig. 26. - Zeidler 2003: 43 View Cited Treatment , figs. 18 - 19.

Material examined. 1 male, 12 females ( DKUAMP20 2407), Taeha-port , Buk-myeon, Ulleung-gun, Gyeongsangbuk-do, Korea, 37°30 ʹ 40 ʺ N, 130°47 ʹ 41 ʺ E, K.W. Kim, by netting, 23 May 2023 GoogleMaps ; 13 males, 38 females, Buk-myeon , Ulleung-gun, Gyeongsangbuk-do, Korea, 37°30 ʹ 29 ʺ N, 130°58 ʹ 11 ʺ E, K.W. Kim, by netting, 24 May 2023 GoogleMaps .

Description. Male (MABIK CR00257941): Body ( Figs. View Fig

9, 10A View Fig ) 4.8 mm long, dorsally smooth; head subequal in length to pereonites 1 - 2; eyes characteristic in form, with ocelli in three rows, shaped ovate; antenna 1 short; antenna 2 minute; coxae flat dorsoventrally, except coxa 7, much shallower than pereonites; pereopods slender, unarmed.

Antenna 1 ( Fig. 10B View Fig ) short, stout, subequal in length to head and pereonites 1 - 2; peduncle strongly compressed, length ratio of peduncular articles 1 - 3 = 1.00: 0.23: 0.21; flagellum 3-articulate, 3.11 × peduncle, article 1 elongated, narrowing distally, articles 2 - 3 minute, terminal article with 1 seta.

Gnathopod 1 ( Fig. 10C View Fig ) short, coxa quadrangular, with rounded corners, width 1.88× length; basis moderate, elongate, anterior margin concave, posterodistal corner slightly produced; ischium subquadrate, 0.24 × basis, posterodistal corner with 2 robust setae; merus short, 0.79× ischium, with 1 robust seta posterodistally; carpus 1.22 × ischium, midposterior margin serrulate, posterodistal corner with 1 tiny robust seta; propodus subrectangular, 1.61 × carpus, posterior margin serrulate; dactylus falcate, inner margin serrulate.

Gnathopod 2 ( Fig. 10D View Fig ) short, carpochelate; coxa subquadrate, width 1.92 × length; basis subrectangular, relatively long, anterior margin slightly concave; ischium short, with 1 robust seta posteriorly; merus 1.44× ischium, posterior and distal margin with robust setae; carpus 1.04× merus, carpal lobe produced, anterior margin of carpal lobe serrulate, with 1 tiny setule distally; propodus slender, subrectangular, 1.46 × carpus, posterior margin serrulate; dactylus falcate, 0.48 × propodus.

Pereopod 3 ( Fig. 10E View Fig ), coxa quadrangular, with round- ed corners, width 1.54 × length; basis subrectangular, unarmed; ischium short, 0.21 × basis; merus subrectangular, 4.19 × ischium; carpus subrectangular, 0.48 × merus; propodus slender, 1.51× carpus, distal half of posterior margin serrulate; dactylus falcate, 0.48× propodus.

Pereopod 4 ( Fig. 10F View Fig ) similar to pereopod 3, but slightly elongated.

Pereopod 5 ( Fig. 10G View Fig ), coxa shallow, subrectangular, with rounded corners, width 3.07× length; basis elongate-ovate; merus slender, elongated, 4.21 × ischium; carpus subrectangular, 0.63 × merus, distal half of anterior and distal margins serrulate; propodus slender, elongated, 1.89 × carpus, anterior margin serrulate; dactylus falcate, 0.48 × propodus, inner margin with 2 accessory teeth.

Pereopod 6 ( Fig. 10H View Fig ) similar to pereopod 5.

Pereopod 7 ( Fig. 10I View Fig ), basis subovate, width 0.75 × length, posterior margin wavy; merus stubby, 3.44 × ischium, anterior margin serrulate, anterodistal lobe present, bifid, serrulate, half of posterior margin serrulate; carpus subrectangular, 1.11× merus; propodus slender, subrectangular, 1.74 × carpus; dactylus slender, blunt, 0.48 × propodus.

Uropod 1 ( Fig. 10J View Fig ), peduncle subrectangular, unarmed, laterodistal and mediodistal corners produced; outer ramus 0.96 × peduncle, both margins with serrations; inner ramus similar to outer ramus in shape and length.

Uropod 2 ( Fig. 10J View Fig ) shorter than uropod 1, peduncle subrectangular, mediodistal corner produced; outer ramus 1.08 × peduncle, proximal half of medial margin serrulate, distal half of lateral and medial margins with serrations; inner ramus 0.83 × outer ramus, medial margin serrulate.

Uropod 3 ( Fig. 10J View Fig ) subequal to uropod 2, peduncle subrectangular, widening distally, laterodistal and mediodistal corners produced; outer ramus short, 0.63 × peduncle, medial margin serrulate; inner ramus 0.94 × outer ramus, medial margin serrulate.

Telson ( Fig. 10J View Fig ) small, entire, subtriangular, unarmed.

Remarks. Vibilia australis Stebbing, 1888 is similar to V. armata Bovallius, 1887 and V. caeca Bulycheva, 1955 in having pointed distal apex of antenna 1. However, V. australis is distinguished from its congeners based on the following features (different characteristics of V. armata and V. caeca in brackets): 1) eyes with ocelli in three rows (vs. ovate in V. armata and absent in V. caeca ); 2) antenna 1 ventral margin straight (vs. proximoventral margin convex in V. armata , distoventral margin concave in V. caeca ); 3) antenna 2 short (vs. elongated in V. armata ); 4) gnathopod 2, propodus anterior margin smooth (vs. serrated in V. armata ); 5) pereopod 7, basis elongate, length subequal to ischium to half of propodus combined (vs. subequal to ischium to carpus combined in V. armata and V. caeca ). Our specimens are accorded with the previous descriptions of Stebbing (1888) and Zeidler (2003).

Distribution. Korea (Ulleungdo Island), tropical and temperate regions.