Aoroides longimerus Ren & Zheng, 1996

8. Aoroides longimerus Ren & Zheng, 1996 View in CoL

ŭẍṈǖ앞ėăNjẹ (ṵÿ)** ( Figs. 2 - 4 View Fig View Fig )

Aoroides longimerus Ren & Zheng, 1996: 59 View in CoL , fig. 2. - Ariyama, 2004: 23, figs. 16 - 19.

Material examined. Adult male, 3.2 mm, Jeodong-port , Buk-myeon, Ulleung-gun, Gyeongsangbuk-do, Korea, 37° 30 ʹ 48 ʺ N, 130°55 ʹ 10 ʺ E, Y.H. Kim, by sieving from fishing gear, 23 May 2023; 1 male GoogleMaps , Jeodong-port , Buk-myeon, Ulleung-gun, Gyeongsangbuk-do, Korea, 37°29 ʹ 38 ʺ N, 130° 54 ʹ 38 ʺ E, Y.H. Kim, by port survey, 24 August 2023 GoogleMaps .

Description. Male (MABIK CR00257939): Body ( Figs. 2 View Fig , 3A View Fig ) 3.2 mm long, dorsally smooth; eyes well developed, ovate.

Antenna 1 ( Fig. 3B View Fig ) slender, elongated, less setose, length ratio of peduncular articles 1 - 3 = 1.00: 1.11: 0.46; flagellum 15-articulate, 1.33 × peduncle; accessory flagellum absent.

Antenna 2 ( Fig. 3C View Fig ) moderate, densely setose; gland cone pointed; peduncular articles 1 - 3 short, peduncular articles 4, 5 subrectangular; length ratio of peduncular articles 3 - 5 = 1.00: 2.75: 2.67; flagellum 3-articulate, each article with 1 or 2 robust setae distally.

Gnathopod 1 ( Fig. 3D View Fig ) characteristic in form, massive, merochelate, densely setose, much larger than gnathopod 2; coxa subtriangular, width 2.19 × length, with 1 robust and 4 plumose setae on anterodistal corner; basis relatively long, widening distally, anterior margin with numerous plumose setae, distal half of lateral margin with a row of plumose setae; ischium short, 0.37 × basis, medial margin with 1 plumose seta; merus slender, elongate, 2.67 × ischium, located below carpus, narrowing distally, apex acute, anterior and posterior margins with numerous plumose setae; carpus elongate-ovate, stout, 0.96 × merus, anterior margin with 12 plumose setae, posterior margin with numerous plumose setae; propodus slender, slightly curved anteriorly, 0.67 × carpus, anterior margin with 13 simple setae, posterior margin with numerous setae; dactylus elongate, falcate, 1.14 × propodus, posterior margin with 17 simple setae.

Gnathopod 2 ( Fig. 4A) subchelate; coxa subquadrate, width 0.85 × length; basis subrectangular, widening distally, slightly curved posteriorly, anterior margin with 12 simple setae, posterior margin with 4 simple setae; merus short, 1.71 × ischium, with simple 12 setae posterodistally; carpus subtriangular, widening distally, 1.79 × merus, anterior margin with 6 simple setae, half of posterior margin setose; propodus subrectangular, 0.88 × carpus, anterior margin with 10 simple setae, posterior margin with 1 robust and 16 simple setae, palm steeply angled; dactylus falcate, overreaching palm, 0.68 × propodus.

Pereopod 3 ( Fig. 4B), coxa subquadrate, width 0.91 × length, posteroventral corner with 5 simple setae; basis subrectangular, slightly widening distally, anterior margin with 9 simple setae, posterior margin with 5 simple setae; merus subrectangular, 1.93 × ischium; carpus subrectangular, 1.04 × merus; propodus slender, subrectangular, 1.19 × carpus; dactylus falcate, 0.61 × propodus.

Pereopod 5 ( Fig. 4C), coxa bilobate, wider than long, anterior lobe broadly rounded, protruding downward; basis elongate-ovate, slightly narrowing distally; ischium short, 0.21 × basis, anterior margin with 3 setae; merus subrectangular, slightly widening distally, 2.33 × ischium; carpus rectangular, 0.86 × merus, with 5 simple setae anterodistally, 2 robust and 3 simple setae posterodistally; propodus slender, slightly widening distally, 1.98 × carpus, anterior margin with 2-2-4 robust setae formula; dactylus falcate, 0.43 × propodus, posterior margin with 1 seta.

Pereopod 6 ( Fig. 4D) similar to pereopod 5, but propodus with 1-2-2-2-2 robust setae formula.

Pereopod 7 ( Fig. 4E) elongated, much longer than either pereopods 5 or 6; basis elongate-ovate, moderately expanded anteroposteriorly; ischium short, 0.25 × basis; merus subrectangular, 3.44 × ischium, anterior margin with 5 simple setae, posterior margin with 3 robust setae; carpus subrectangular, 0.72 × merus; propodus elongate, 1.42 × carpus, anterior margin with 2-2-1 robust setae formula, posterodistal corner with 10 simple setae; dactylus falcate, 0.41 × propodus, posterior margin with 1 seta.

Uropod 1 ( Fig. 4F), peduncle subrectangular, length 0.89 × inner ramus, with 3 dorsolateral, 4 dorsomedial robust setae, and a large inter-ramal process; outer ramus × 1.09 inner ramus, dorsal margin with 5 robust setae, 4 robust setae on apex; inner ramus with 5 dorsal and 4 apical robust setae.

Uropod 2 ( Fig. 4G), peduncle subrectangular, length 0.81 × inner ramus, with 1 dorsolateral and 2 dorsomedial robust setae; outer ramus× 1.12 inner ramus, with 5 dorsal and 4 apical robust setae; inner ramus with 4 dorsal and 4 apical robust setae.

Uropod 3 ( Fig. 4H) short, × 0.59 uropod 2; peduncle subequal to outer ramus, with 3 dorsolateral, 1 dorsomedial simple setae, and 2 apicodorsal robust setae; outer ramus subequal to inner ramus, biarticulate, proximal article with 1 dorsal robust seta and 3 simple setae subapically, terminal article short, with 4 simple setae on apex; inner ramus with 2 robust setae.

Telson ( Fig. 4I) short and fleshy, trapezoidal, narrowing distally, broader than long, truncate apically, with 6 unequal simple setae dorsally and 2 short setae apically.

Remarks. Aoroides longimerus Ren & Zheng, 1996 is similar to A. ellipticus Ariyama, 2004 , A. myojinensis Ariyama, 2004 , and A. secunda Gurjanova, 1951 in having densely setose anterior margins of basis and carpus of gnathopod 1. However, A. longimerus is distinguished from its congeners based on the following features (different characters of A. ellipticus , A. myojinensis , and A. secunda in brackets): 1) gnathopod 1, coxa with four plumose setae and a robust seta anterodistally (vs. 1 long robust seta in A. ellipticus , unarmed in A. myojinensis , and 2 robust setae in A. secunda ); 2) gnathopod 1, carpus elongate-ovate (vs. ovate in A. myojinensis and A. secunda ); 3) pereopod 3, basis anterior margins sparse with simple setae (vs. setose with plumose setae in A. secunda ); 4) pereopod 7, basis slender, elongate ovate (vs. moderate, ovate in A. ellipticus ); 5) uropod 3, both rami with robust setae (vs. inner ramus with a robust seta in A. ellipticus , both rami unarmed in A. secunda ). The newly recorded species in Korea, A. longimerus , is well accorded with Ren & Zheng’s original description.

Distribution. Korea (Ulleungdo Island), Japan, China.

Family Caprellidae Leach, 1814 fiµ1ḑNjâ

Genus Caprella Lamarck,1801 fiµ1ḑNjẃ