Indoapseudes bamberi, Kakui, Keiichi & Naruse, Tohru, 2015

Kakui, Keiichi & Naruse, Tohru, 2015, Indoapseudes bamberi sp. nov. (Crustacea: Tanaidacea: Pagurapseudidae: Hodometricinae) from Iriomote Island, Ryukyu Islands, southwestern Japan, Zootaxa 3995 (1), pp. 138-148 : 139-146

publication ID	https://doi.org/ 10.11646/zootaxa.3995.1.14
publication LSID	lsid:zoobank.org:pub:74133FCC-BE5A-4DC5-B52A-A06A3F6FFC59
DOI	https://doi.org/10.5281/zenodo.5669259
persistent identifier	https://treatment.plazi.org/id/696787D9-1104-FF91-3AAE-FA28F9A399D8
treatment provided by	Plazi
scientific name	Indoapseudes bamberi
status	sp. nov.

Treatment

Indoapseudes bamberi View in CoL sp. nov.

( Figs 1–7 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Material examined. Holotype - preparatory female (ZIHU-4945, BL 2.67, CW 0.40, seven slides and one vial), RV Miyama II, Funaura Bay, Iriomote Island, Ryukyu Islands, Japan, 24°26.522′N, 123°49.390′E to 24°26.545′N, 123°49.316′E, 30 m, biological dredge, 5 July 2014, collected by K. Kakui.

Diagnosis. Antennal squama present; pereopods 1 and 2 with one dorsal spine on basis.

Etymology. The species is named for Roger N. Bamber in recognition of his great contributions to tanaidacean taxonomy.

Description. Female holotype. Body ( Fig. 1 View FIGURE 1 ; 2A, B1–5) flattened dorsoventrally, 6.6 times as long as wide. Cephalothorax 0.2 times BL, 1.2 times as long as wide, with several pairs of simple setae. Posterior region with one dorsal median round tubercle. Eye lobes well defined, not fused to carapace, without ommatidia. Anterior edge of carapace denticulate. Projection on clypeus single, spiniform. Somite that supports chelipeds with ventral serrate keel in midline (arrow, Fig. 2 View FIGURE 2 a1, 7). Pereonites each with several dorsal simple setae; pereonites 1 and 2 each with ventral spine; pereonites 1–4 with two, two, three, and two pairs of spines, respectively; pereonite 4 longest among pereonites. Pleon 0.2 times BL, 0.4 times pereon width. Pleonites all wider than long, with single setae and smooth lateral edge. Pleotelson 2.1 times as long as wide, longer than pleonites 1–5 combined; middle region with a pair of slight tubercles with one simple seta and one distal PSS; posterior tip with two spines.

Antennule ( Fig. 3 View FIGURE 3 A) 2.7 times cephalothorax length; length ratio of articles 1–4, inner flagellum, and outer flagellum 1.00:0.16:0.27:0.06:0.48:0.77. Article 1 with several simple setae, several PSS, several inner spines on edge scattered along entire length, several outer spines on edge in proximal two-fifths, one outer distal spine, and one dorsodistal spine. Article 2 with one inner medial and four distal simple setae and several distal PSS. Article 3 with three medial and four distal simple setae and one proximal PSS. Article 4 with one PSS, and one simple seta at insertion of inner flagellum. Outer flagellum with seven articles; articles 1–7 with zero, three, three, four, one, two, and four distal simple setae, respectively; articles 4 and 7 with one and two middle simple setae, respectively; articles 3, 4, 6 each with one distal aesthetasc; article 7 with one distal PSS. Inner flagellum with five articles (article 5 tiny); articles 1–5 with one, two, one, one, and two distal simple setae, respectively; articles 1–4 each with one PSS. Antenna ( Fig. 3 View FIGURE 3 B) with eight articles; 0.50 times antennule length; length ratio of articles 1–8, 0.36:1.00:0.26:0.82:0.81:0.22:0.31:0.25. Article 1 with inner distal lobe bearing one simple seta. Article 2 with one outer and two inner simple setae, and four inner spines. Article 3 with one inner simple seta and one inner distal spine. Article 4 with two PSS. Article 5 with one inner distal simple seta and several PSS. Article 6 naked. Article 7 with one simple seta and one PSS. Article 8 with four simple setae. Squama present, shorter than half article 3 length, with two distal simple setae.

Labrum ( Fig. 3 View FIGURE 3 C) with fine setae as illustrated; distal margin concave, serrate. Mandibles ( Fig. 3 View FIGURE 3 D–G) with molar process well developed, bearing distal row of denticles; body with one simple seta. Left mandible incisor ( Fig. 3 View FIGURE 3 D) with four teeth; setiferous lobe with five complex setae; lacinia mobilis with four teeth. Right mandible incisor ( Fig. 3 View FIGURE 3 E) with three teeth; setiferous lobe with one trifurcate seta and six complex setae. Palp ( Fig. 3 View FIGURE 3 G) with three articles; article 1 bent dorsally, with one simple and one plumose setae ventrally; article 2 with seven simple, one plumose, and three pinnate setae in ventral region; article 3 with one middle and one distal simple setae, and eight ventral pinnate setae. Labium ( Fig. 3 View FIGURE 3 H) with lobe bearing inner distal setation. Palp setulate, with one simple and one multifurcate seta at tip. Maxillule ( Fig. 4 View FIGURE 4 A–C) with palp bearing three subdistal (setulate; tips lost) and one distal (plumose and hook-tipped) setae. Outer endite ( Fig. 4 View FIGURE 4 B) with outer and inner clumps of simple setae, one subdistal serrate seta, and twelve distal spiniform setae (one bifurcate; one serrate). Inner endite ( Fig. 4 View FIGURE 4 C) with one outer process, inner row of short setae, and outer clump of simple setae; distal region with four pinnate setae and one trifurcate seta. Maxilla ( Fig. 4 View FIGURE 4 D, d1–3) with inner lobe of fixed endite bearing ca. 20 bifid-tipped setae and five biserrate setae; outer lobe of fixed endite ( Fig. 4 View FIGURE 4 d1) with five simple setae, four upswept serrate setae (one with large blades), one setulate seta, three trifurcate spiniform setae (arrows, Fig. 4 View FIGURE 4 d1), and two ventral branched setae (arrowheads, Fig. 4 View FIGURE 4 d1, d3); inner lobe of movable endite with four simple and seven pinnate setae; outer lobe of movable endite ( Fig. 4 View FIGURE 4 D, d2) with two subdistal pinnate, medially serrate setae; distal region with two pinnate, medially serrate setae and six pinnate setae. Maxilliped ( Fig. 4 View FIGURE 4 E, e1) with coxa. Basis with three ventral plumose setae and two outer spiniform setae. Endite with two ventral plumose setae, nine complex spiniform setae, and setulation in distal region; outer region smooth; inner region with nine basally setulate setae and three coupling hooks. Palp article 1 naked; article 2 with one outer distal simple seta, 13 inner marginal simple setae, and one ventral plumose seta; article 3 with nine simple setae in inner region; article 4 with two subdistal setae and one distal simple seta, and eight distal serrate setae. Epignath ( Fig. 4 View FIGURE 4 F) cup-shaped; terminal seta setulate in distal region.

Cheliped ( Fig. 5 View FIGURE 5 A, a1) basis 3.2 times as long as wide, with several simple setae, one distal plumose seta, and one proximal, one middle and one distal spines in ventral margin; dorsal region with three simple setae, one proximal spine, and several rows of small spines. Merus with one ventral and one subdistal simple seta, one dorsodistal and two ventrodistal plumose setae, and one ventral spine. Carpus ca. six times as long as wide, 1.86 times basis length; dorsal region with 14 simple setae and one distal spine; ventral region with eleven simple setae and eight spines. Propodal palm with four dorsal, one outer, two inner, and two ventral simple setae. Fixed finger with four ventral, one inner ventral, and four outer ventral simple setae; cutting surface with seven outer and two inner simple setae, and eight biserrate lamellar setae; claw with inner row of spines ( Fig. 5 View FIGURE 5 a1). Dactylus as long as fixed finger, with one dorsal, two outer, and four inner simple setae; cutting surface with three simple setae and four spiniform setae; claw with comb-like expansion. Exopod with three articles; distal article with three plumose setae.

Pereopods 1–6 cylindrical, with length ratio of 1.18:1.15:1.00:1.07:1.14:1.16; pereopods 1–4 with oostegites. Pereopod 1 ( Fig. 6 View FIGURE 6 A) 0.43 times BL, without exopod. Coxa with one simple and three plumose setae, and dorsal spine. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 4.39:0.42:1.00:2.22:1.58:1.01. Basis with several simple setae, several PSS, one dorsal curved spine, and inner proximal hook-like apophysis (cf., Bamber 2005: fig. 18D; not illustrated in Fig. 6 View FIGURE 6 A). Ischium with two ventral simple setae. Merus with two dorsal and four ventral simple setae. Carpus with five dorsal and eight ventral simple setae, and eight ventral spiniform setae. Propodus with five ventral simple setae, one dorsodistal and seven ventral spiniform setae, one dorsal PSS, and five serrate setae. Dactylus with two dorsal, two ventral, and one ventrodistal simple setae. Unguis naked. Pereopod 2 ( Fig. 6 View FIGURE 6 B) with coxa bearing two simple setae and one dorsal spine. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 4.01:0.43:1.00:2.26:1.57:0.86. Basis, merus, carpus, and dactylusunguis similar to those of pereopod 1; ischium with one ventral simple seta, carpus with five ventral simple setae and nine ventral spiniform setae, and dactylus with one ventral seta. Propodus with three dorsal and three ventral simple setae; one dorsal, four outer, and five ventral spiniform setae; and one dorsal PSS. Pereopod 3 ( Fig. 6 View FIGURE 6 C) with coxa naked. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 3.17:0.46:1.00:1.85:1.49:0.55. Basis with several simple setae and several PSS. Ischium with one dorsal and one ventral simple seta. Carpus, propodus, and dactylus-unguis similar to those of pereopod 2, merus with three ventral simple setae, carpus with eight ventral spiniform setae, propodus with four ventral simple setae and three outer spiniform setae, and dactylus with one dorsal simple seta.

Pereopod 4 ( Fig. 6 View FIGURE 6 D, d1) with coxa naked. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 4.01:0.31:1.00:1.71:1.85:0.97. Basis, ischium, merus and dactylus-unguis similar to those of pereopod 3, except merus with one dorsal simple seta but without outer setae, and dactylus with two dorsal simple setae. Carpus with four dorsal and seven (five apparently thicker than the others) ventral simple setae, and one ventrodistal spiniform seta. Propodus with one dorsal and three ventral simple setae, four ventral spiniform setae, and one dorsal PSS; distal region ( Fig. 6 View FIGURE 6 d1) with one ventrodistal spiniform seta, two pinnate setae, and four dorsosubdistal, four dorsodistal, and one ventrodistal serrate setae. Pereopod 5 ( Fig. 6 View FIGURE 6 E, e1) with coxa bearing two simple setae. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 3.76:0.30:1.00:2.21:1.73:0.79. Basis, ischium, merus, and dactylus-unguis similar to those of pereopod 4, except ischium lacking dorsal seta, merus with two dorsal and three ventral simple setae, and dactylus with two ventral simple setae. Carpus with three dorsal and nine (three apparently thicker than the others) simple setae. Propodus with three dorsal and three ventral simple setae, five ventral spiniform setae, one dorsal PSS, and one inner row of seven spiniform setae ( Fig. 6 View FIGURE 6 e1). Pereopod 6 ( Fig. 6 View FIGURE 6 F) with coxa bearing one simple seta. Length ratio of basis, ischium, merus, carpus, propodus, and dactylus-unguis 3.78:0.40:1.00:2.20:1.65:0.79. Basis, ischium, merus, and dactylus-unguis similar to those of pereopod 5, except dactylus with two dorsal simple setae. Carpus with four dorsal and seven (four apparently thicker than others) simple setae. Propodus with four dorsal and three ventral simple setae, four ventral spiniform setae, and one dorsal PSS.

Pleopods absent.

Uropod ( Fig. 6 View FIGURE 6 G) with basal article bearing two middle and four distal simple setae. Endopod and exopod broken.

Genetic information. The COI sequence (652 bp, translated into 217 amino acids) was determined from the holotype specimen; the International Nucleotide Sequence Databases (INSD) accession number LC005412 View Materials .

Distribution. So far, this species is known only from the type locality.

Remarks. Indoapseudes bamberi sp. nov. is the sixth described member of Indoapseudes . Indoapseudes bamberi differs from all its congeners in having an antennal squama, and in having only one dorsal spine on the bases of pereopods 1 and 2. In addition, it differs from I. brycesoni in having the eye lobe without ommatidia ( Băcescu 1976a: 7 noted I. brycesoni has “brown eyes”), and the antennular article-1 without outer spines in the distal region. Indoapseudes bamberi differs from I. secundus in the shape of the anterior edge of the carapace (denticulate in I. bamberi ; with short, acute rostrum in I. secundus ), the ornamentation in the middle region of the pleotelson (a pair of slight tubercles in I. bamberi vs. a pair of acute spines in I. secundus ), and the ornamentation on the chelipedal basis (three ventral and one dorsal spines, and dorsal rows of spines in I. bamberi vs. two ventral and six dorsal spines in I. secundus ); I. bamberi differs from I. macabre in the shape of anterior edge of carapace (denticulate in I. bamberi ; with short, acute rostrum in I. macabre ), the presence ( I. macabre ) or absence ( I. bamberi ) of ommatidia in the eye lobe, and the presence ( I. macabre ) or absence ( I. bamberi ) of outer spines in the distal region of the antennular article 1.

Among the genus, I. multituberculata is the only species having pleopods 4 and 5 in females. Although this character casts uncertainty on its generic affiliation, we retain it in Indoapseudes for now. Besides the unique character states of I. bamberi and I. multituberculata mentioned above, these two species differ in the ornamentation on the chelipedal basis (three ventral spines in I. bamberi vs. one ventral spine in I. multituberculata ) and carpus (eight ventral spines in I. bamberi vs. one ventroproximal and one ventrodistal spines in I. multituberculata ), and in the number of pereopods with dorsal spine(s) on the basis (pereopods 1 and 2 in I. bamberi vs. all pereopods in I. multituberculata ).

The only deep-sea member of Indoapseudes , I. choristhema is unique in the following character states: 1) the cheliped lacks an exopod; 2) the antenna lacks a “flagellum”, which corresponds to articles distal to article 5 in this genus (articles 6–8 in I. bamberi ; Fig. 3 View FIGURE 3 B); 3) the pleonites bear dorsal spines; 4) article 2 of the maxillipedal palp has coarse denticulation on the outer surface; and 5) the uniramous uropod [Bamber (2007: 68) considered I. choristhema to lose the uropodal endopod]. Although these definitive differences suggest that a new genus is warranted for I. choristhema , this will require re-examination of the type specimens.

The character states unique to I. choristhema mentioned above suggest that it is more closely related to the metapseudid genus Curtipleon Băcescu, 1976 , than to its congeners. Curtipleon established by Băcescu (1976b) in the family Metapseudidae Lang, 1970 has all the pleonites fused to the pleotelson, but it shares many features with Hodometricinae , e.g., the long, spiny antennular article 1; narrow, cylindrical pereopods 1–6; and the strongly calcified body. Additionally, a structure similar to the ventral serrate keel seen on the somite with chelipeds in I. bamberi [ Figs 2 View FIGURE 2 a1, 7; this might correspond to the “serrated anteriorly curved huge hyposphenium like the keel of a vessel” in I. brycesoni ( Băcescu 1976a: p. 6)] has been observed in a female specimen of Curtipleon that bears two rows of serration on the keel (K. Kakui unpublished data). Guţu (2006: p. 30) suggested that the shape of the keel [= hyposphenium in Guţu (2006)] is important in delineating some genera; he also noted its similarity among confamilial genera. The similarities noted above between Curtipleon and Hodometricinae (at least Indoapseudes ) suggest that, although they are currently placed in different families, these two taxa are phylogenetically closely related.