Paramphilochus parachelatus Ishimaru & Ikehara, 1986

Lee, Kyung-Sook, 2010, A new species and new record of the Amphilochidae (Crustacea: Amphipoda) from Korea, Zootaxa 2477, pp. 21-36: 31-35

publication ID

http://doi.org/ 10.5281/zenodo.893974

persistent identifier

http://treatment.plazi.org/id/B72787B7-BA00-FFAD-FF35-EA37FC68FE3C

treatment provided by

Plazi

scientific name

Paramphilochus parachelatus Ishimaru & Ikehara, 1986
status

 

Paramphilochus parachelatus Ishimaru & Ikehara, 1986  ( Figures 6–8View FIGURE 6View FIGURE 7View FIGURE 8) (Korean Name: Nae-min-son-jjal-eun-kko-ri-yeop-sae-u, new)

Paramphilochus parachelatus Ishimaru & Ikehara, 1986  , p. 193, figs. 1–3; Ishimaru, 1990, p. 212, fig. 3.

Material examined. 4 specimens, Daejung Jejudo Is., 13 August 2003, algal wash, collector Y.H. Kim; 11 specimens, Daebo, Pohang-si, 26 August 2005, algal wash, collector Y.H. Kim; 3 ♀, Gajin, Goseong-gun, 20 October 2005, light trap, collector Y.H. Kim; 1 specimen, Dapo Port., Geojedo Is., 13 June 2008, light trap, collector Y.H. Kim; 3 specimens, Buheung-ri, Yeougdeok-gun, 20 June 2008, light trap, collector Y.H. Kim; 1 specimen, Jijuk Port, Goheung-gun, 25 June 2008, light trap, collector Y.H. Kim; 7 specimens, Sacheon, Gangreung-si, 11 July 2008, algal wash, collector S.S. Hong; 5 specimens, Jungrajin Port, Samcheok-si, 9 August 2008, algal and invertebrate wash, collector K.S. Lee; 1 specimen, Gonghyeonjin Port, Goseong-gun, 13 March 2009, algal and invertebrate wash, collector Y.H. Kim; 3 specimens, Seodo-ri, Geomundo Is., 16 April 2009, light trap, collector Y.H. Kim.

Description. ♀. Body ( Figs. 6View FIGURE 6, 7AView FIGURE 7) dorsally smooth, 3.3 mm long.

Head ( Fig. 7AView FIGURE 7) slightly longer than pereonite 1; eye elliptical, medium to large size, with core of black pigment in alcohol; rostrum well developed, reaching distal end of peduncular article 1.

Antenna 1 ( Fig. 7BView FIGURE 7) length ratio of peduncular articles 1–3 = 1.00: 1.00: 0.60, article 1 slightly wider than article 2; article 3 bearing coniform, 1-articulate accessory flagellum, 0.33 x length of flagellum article 1, with 2 unequal setae and tiny penicillate seta distally; primary flagellum 8-articulate, 0.91 x length of peduncular articles, each article with 1 or 2 long aesthetascs, respectively.

Antenna 2 ( Fig. 7CView FIGURE 7) subequal in length to antenna 1; peduncular articles 1 and 2 short, article 4 subequal in length to article 5; flagellum 9-articulate, slightly shorter than peduncular articles.

Gnathopod 1 ( Fig. 7DView FIGURE 7) coxa ovate, mostly hidden by coxa 2; basis rectangular; ischium 0.66 x length of merus; carpal lobe extending about 0.5 x along ventral margin of propodus, narrowly triangular, medially and distally with 3 setae; propodus about 0.7 x as wide as long, 4.1 x length of carpus, palm nearly transverse, convex, finely serrulate, with a row of feeble setae, palm corner defined by a pair of distal spines; dactylus about 0.6 x as long as propodus, nearly reaching palm corner, with a small inner marginal tooth subdistally. Gnathopod 2 ( Fig. 7EView FIGURE 7) similar to gnathopod 1, but carpus and propodus of a different shape; coxa 2 subrectangular, ventral margin rounded; carpus very short, length 0.22 x propodus, carpal lobe very small, not guarding ventral margin of propodus; propodus parachelate, gradually widening distally, palm jutting obtusely forward; palm transverse, corner defined by a pair of distal spines; dactylus fitting palm, with a small tooth subdistally.

Pereopod 3 ( Fig. 7FView FIGURE 7) coxa similar to coxa 2, with setules ventrally; basis rectangular, bearing feeble setae on anterior margin and 1 seta posterodistally; merus 1.37 x length of carpus, anterodistal corner protruding; posterior margins of merus to propodus with sparse clusters of setae; dactylus 0.38 x length of propodus, inner margin with distal tooth.

Pereopod 4 ( Fig. 7GView FIGURE 7) similar to pereopod 3 except coxa broadened, posterior margin excavate.

Pereopod 5 ( Fig. 8AView FIGURE 8) coxa broad, posterolobate, anterior margin broadly convex, posterior lobe narrowed; basis broadly rounded, expanded posteriorly, anterior margin with 2 rows of short spines, posterior margin with minute setules, posterodistal corner rounded; ischium 0.47 x length of merus, with 2 spines anteriorly; merus 1.14 x length of carpus, posterodistal corner overhanging; propodus as long as merus, longer than carpus, with row of anterior spines, with feeble posterior marginal setae.

Pereopod 6 ( Fig. 8BView FIGURE 8) similar to pereopod 5, but the anterior margin of coxa 6 is straight, articles are slightly wider and propodus is longer.

Pereopod 7 ( Fig. 8CView FIGURE 8) coxa small, ventral margin rounded; basis slightly broader than those of pereopods 5–6; articles 5–7 missing.

Epimeron 1 ( Fig. 8DView FIGURE 8) subtriangular, posteroventral corner with small cusp.

Epimeron 2 ( Fig. 8DView FIGURE 8) subrectangular, ventral margin with 4 spines; posteroventral corner with small cusp.

Epimeron 3 ( Fig. 8DView FIGURE 8) subrectangular, ventral margin with 2 spines, posteroventral corner with small cusp.

Uropod 1 ( Fig. 8EView FIGURE 8) peduncle longer than rami, 1.22 x length of inner ramus, with 11 dorsolateral, 2 dorsomedial and 1 apicomedial spine; outer ramus 0.86 x length of inner ramus, with 3 dorsolateral marginal spines; inner ramus with 3 dorsolateral and 3 dorsomedial spines.

Uropod 2 ( Fig. 8FView FIGURE 8) peduncle short, 1.2 x length of outer ramus, with 5 dorsolateral and 1 apicomedial spines; outer ramus short, 0.71 x length of inner ramus, with 3 dorsolateral spines; inner ramus with 3 dorsolateral and 2 dorsomedial spines.

Uropod 3 missing.

Telson ( Fig. 8GView FIGURE 8) linguiform, triangular, 1.65 x as long as wide, apically broadly rounded, with 2 pairs of penicillate setae on middorsal surface.

Remarks. In general, our specimens show many morphological similarities to the original description and figures of Ishimaru & Ikehara (1986). However, our specimens also display some important differences, such as the shorter carpal lobe of gnathopod 1, gnathopod 2 propodus broader, epimeron 1–3 bearing weakly toothed posteroventral corners (vs not toothed), uropod 2 outer ramus longer and the telson rounded apically (vs acutely pointed). However, as we have not had the opportunity to examine the type material of Ishimaru & Ikehara (1986), we cannot confidently determine whether our species is novel. Therefore at this time we conservatively maintain our Korean specimens as P. parachelatus  until a detailed, comparative study can be made on the type material.

Distribution. Korea (Jejudo Island, south and east coasts), Japan.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Amphipoda

Family

Amphilochidae

Genus

Paramphilochus

Loc

Paramphilochus parachelatus Ishimaru & Ikehara, 1986

Lee, Kyung-Sook 2010
2010
Loc

Paramphilochus parachelatus

Ishimaru & Ikehara 1986
1986