Iphinoe indenticulata Kim & Kim, 2020

Iphinoe indenticulata Kim & Kim, 2020

( Fig. 5 View FIGURE 5 )

Kim & Kim, 2020, 307– 316, fig. 1–4, table 1 (male description).

Diagnosis. Ovigerous female. Carapace 0.24–0.25 times total body length, 1.9–2.1 times as long as wide, 2.0–2.2 times depth. median dorsal ridge strong at anterior, weak at posterior region, with 14–20 teeth for entire length of carapace; width of triangular eye lobe 0.12–0.16 times carapace width, 1.5–1.7 times eye lobe length; antero-lateral angle succeeded by 4–6 teeth; inferior margin smooth, without teeth. Pereopod 1 basis 1.1–1.2 times as long as distal articles together; dactylus shorter than carpus; propodus with 4–6 long simple seta on inner distal region. Uropod peduncle with long plumose setae and spiniform setae on inner margin. Adult male. Carapace median dorsal ridge very weak or obsolete, without spines; antero-lateral angle with 3–4 teeth; inferior margin without teeth. Antenna 1 main flagellum article 1 with 6–8 aesthetascs.

Material examined. 86 ovigerous females, 26 preparatory females, 9 adult males, 3 subadult males (including dissected 5 ovigerous females, 6.1–7.2 mm, 3 adult males, 6.9–7.5 mm) ( NSMT Cr- 32965), off Ushimado , the Seto Inland Sea of Japan, 34°35'N, 134°09'E, 15 m, 15 April, 1998 GoogleMaps .

Description. Five ovigerous females, 6.1–7.2 mm ( Fig. 5 View FIGURE 5 ). Body moderately calcified, with few hairs, integument glossy. Carapace ( Fig. 5A–D View FIGURE 5 ) 0.24–0.25 times total body length, 1.9–2.1 times as long as wide, 2.0–2.2 times depth; dorsal surface with median ridge running for entire length of carapace, posterior half weak, with 14–20 teeth; pseudorostrum ( Fig.5B, D View FIGURE 5 ) 0.12–0.15 times carapace length; width of rather triangular eye lobe ( Fig5B, D View FIGURE 5 ) 0.12–0.16 times carapace width, 1.5–1.7 times eye lobe length; antennal notch ( Fig. 5C View FIGURE 5 ) prominent; antero-lateral angle round, with 4–6 teeth; lower margin of carapace smooth. Pereon 1.06–1.13 times carapace length; pereonite 2 well developed. Pleon 0.48–0.50 times total body length; without ridges.

Antenna 1 ( Fig. 5E View FIGURE 5 ) peduncle almost naked, article 1 weakly curved, 1.4–1.6 times as long as article 2, 0.9–1.0 times as long as article 3; article 3 1.6 times as long as article 2, with two broom setae on distal corner; main flagellum biarticulate, 0.4 times as long as peduncle article 3, article 1 2.8–3.2 times as long as article 2; accessory flagellum uniarticulate, 0.3–0.5 times as long as main flagellum article 1.

Antenna 2 ( Fig. 5F View FIGURE 5 ) biarticulate, basal article with 3–4 pappose setae on distal and lower margin.

Mandibles, maxilla 1 and 2, maxilliped 1 similar to males described in Kim & Kim (2020). Maxilliped 2 coxa ( Fig. 5G View FIGURE 5 ) rudimentary oostegite weakly bent, with 11–13 setae.

Maxilliped 3 ( Fig. 5H View FIGURE 5 ) basis 1.8–2.0 times as long as distal articles together, with 3–5 plumose setae on inner distal region, outer distal corner strongly projected reaching median region of carpus, with 9–13 plumose setae; ischium naked; merus with one plumose and two simple setae on outer distal region; carpus with 3–4 setae on inner margin; propodus with five simple setae on inner distal corner; dactylus with 3–5 terminal setae; well-developed exopod, flagellum of five articles.

Pereopod 1 ( Fig. 5I View FIGURE 5 ) basis 1.1–1.2 times as long as distal articles together, outer margin coarsely serrated with 17–21 teeth; ischium with plumose seta on inner distal corner; carpus 1.1–1.6 times as long as merus, 0.9– 1.2times as long as propodus; propodus 1.0–1.1 times as long as dactylus, with 4–6 long simple setae on inner distal region; dactylus 0.8–1.0 times as long as carpus, with 3–4 terminal setae; well-developed exopod flagellum of five articles.

Pereopod 2 ( Fig. 5J View FIGURE 5 ) basis 0.7–0.8 times as long as distal articles together, with 5–7 plumose setae on inner margin and 3–6 plumose setae on outer margin; merus with robust seta on distal end and plumose seta on inner margin; carpus 1.0–1.2 times as long as merus; dactylus 1.0–1.2 times as long as carpus, 2.3–2.8 times as long as propodus, with 6–8 setae.

Pereopod 3 ( Fig. 5K View FIGURE 5 ) basis 1.1–1.4 times as long as distal articles together, with 4–5 plumose setae on lateral margin; ischium with 3–5 simple setae on distal corner; carpus with 3–5 simple setae on distal region; dactylus small.

Pereopod 4 ( Fig. 5L View FIGURE 5 ) basis 0.8–1.0 times as long as distal articles together, with 2–3 plumose setae on lateral margin, three plumose setae on distal corner; ischium with 3 – 4 simple setae on distal corner; carpus with 6 simple setae on distal region; dactylus small.

Pereonite 5 ( Fig. 5M View FIGURE 5 ) basis 0.8–0.9 times as long as distal articles together, with 0–1 simple seta on lateral margin and 2–3 plumose setae on distal corner; ischium with 3–4 simple setae on distal corner; carpus with 4–6 simple setae on distal region; dactylus small.

Uropod ( Fig. 5N View FIGURE 5 ) peduncle 1.4–1.8 times as long as pleonite 6, 1.2–1.5 times as long as exopod and 1.3–1.5 times as long as endopod, with 6–10 spiniform seta and 4–5 plumose setae on inner margin; exopod 1.0–1.1 times as long as endopod, with 3–4 simple and 14–16 plumose setae; endopod biarticulate, article 1 0.7–0.8 times as long as article 2; article 1 with 4–6 spiniform setae on inner margin; article 2 with 6–7 spiniform setae on inner margin and 5–7 plumose setae on outer margin and apex.

Remarks. Male specimens of Iphinoe indenticulata from the Seto Inland sea agree well with the description given by Kim & Kim (2020). Iphinoe indenticulata is distinguished from I. sagamiensis and I. wakasaensis , the other two Japanese Iphinoe species, by (1) the triangular eye lobe, (2) the antenna 1 article 3 is slightly longer relative to article 2 in females, (3) the antenna 1 main flagellum article 1 has more aesthetascs in the adult males, (3) the pereopod 1 basis is longer than combined length of distal articles, and the propodus has more long setae on the inner distal region, (4) the uropod peduncle has long setae on the inner margin in females, and (5) the dorsal surface of the carapace lacks spines ( Table 1).

Iphinoe indenticulata is similar to I. tenera from the Chinese and Korean coasts of the Yellow Sea but is distinguished from the latter by (1) the anterior portion of carapace in females is without a longitudinal ridge, (2) the inner distal region of the pereopod 1 propodus has more setae in females, and (3) the anterolateral angle of the carapace has teeth in males ( Table 1).

Iphinoe indenticulata is also similar to I. gurjanovae from the Chinese coast of the Yellow Sea, 0–37 m, but is distinguished from the latter by (1) the dorsal surface of the carapace has more teeth in females, (2) the pereopod 1 basis outer margin is serrated and the propodus inner distal region has more long setae in females, and (3) the anterolateral corner on the carapace in males has teeth ( Table 1).

Distribution. Seto Inland Sea of Japan, 15 m, muddy bottom. Korea, 2– 5 m.