Indoapseudes multituberculata, Tzeng, You-Wei & Hsueh, Pan-Wen, 2014

Tzeng, You-Wei & Hsueh, Pan-Wen, 2014, New species and records of Apseudomorpha (Crustacea: Tanaidacea) from Taiwan, Zootaxa 3869 (3), pp. 313-337 : 329-336

Indoapseudes multituberculata sp. nov.

Figs 9–12

Material examined. Holotype: non-ovigerous female ( NMNS 7342-1), 2.8 mm, Jihuei (23°06'54.9"N, 121°24'16.3"E), eastern Taiwan, intertidal, washing from red alga Mastophora sp., collected by You-Wei Tzeng, April 18, 2012.

Paratype: one female ( NMNS 7341-2), 1.9 mm, Jihuei (23°06'54.9"N, 121°24'16.3"E), eastern Taiwan, intertidal, washing from red alga Mastophora sp., collected by You-Wei Tzeng, August 8, 2012.

Diagnosis. Female: Body cylindrical, posterior narrower progressively. Cephalothorax subrectangular, rostrum denticulate down-curved. Pleotelson terminal point covered with tubercles. Antennule outer flagellum eight-segmented, inner flagellum five-segmented. Antenna squama absent, flagellum three-segmented. Mandible palp article 1 distal margin with row of teeth. Cheliped carpus slender, with one dorsal and two ventral spine-like apophyses. Pleopods 1–3 absent, last two pairs reduced.

Description. Holotype: Habitus ( Fig. 9 A) body cylindrical and highly calcified, about six times as long as wide. Cephalothorax subrectangular from dorsal view, 1.3 times as long as wide, about 0.2 times as long as body; rostrum denticulate, down-curved; eye lobes well-developed, fully separated from carapace, pigmented. Pereon narrower progressively from pereonites 1 to 6; pereonites 1–3 naked laterally; pereonite 4 longest, with three lateral projections; pereonites 5–6 with two lateral projections. Pleon ( Fig. 9 D) thin cylindrical, narrower than pereonite 6; each pleonite with one pair of dorsal setae. Pleotelson with two dorsal setae, lateral margin with three tubercles and several setae, apex covered with about ten tubercles.

Antennule ( Fig. 9 B) about twice as long as cephalothorax; peduncle article 1 about 0.5 times as long as antennule, outer margin with seven pointed apophyses, one distal large apophysis, and about ten broom setae, inner margin with ten pointed apophyses, one distal apophysis, and one or two broom setae between each apophysis; article 2 with more than eight broom setae; article 3 two times as long as article 2, with four broom setae, one simple seta, and some setules; article 4 naked; outer flagellum eight-segmented, segments 4, 5 and 7 each with one aesthetasc, distal segment with six setae and one broom seta; inner flagellum five-segmented, with four setae and one broom seta.

Antenna ( Fig. 9 C) squama absent, nearly 0.3 times as long as antennule; peduncle five-articled, article 1 inner expansion ovate, with denticulate inner margin, article 2 twice as long as article 1, with single outer broom seta and five acute apophyses on inner margin, article 3 short, with single distal broom seta, article 4 with two broom setae and several setules, article 5 about as long as article 4, with four broom setae and several setules; flagellum threesegmented, segments 1–2 shorter than peduncle article 5, with one distal broom seta on each segment, distal segment shortest, with one broom seta and three long distal simple setae.

Left mandible ( Fig. 9 E) incisor process not studied (body part incomplete); palp three-articled, article 1 with three inner plumose setae and five distal teeth, article 2 with seven inner and five outer setae, article 3 with 13 setae on inner margin. Right mandible ( Fig. 9 F) as left but without lacinia mobilis; setal row of two bifurcate and three multifurcate spiniform setae and one simple seta. Labium ( Fig. 10 A) palp surface covered by numerous long setules and with two distal setae; lobe covered by numerous setules. Maxillule ( Fig. 10 B) outer endite with eleven distal spines and one simple seta, outer margin covered with setules; inner endite with five distal plumose setae; palp present. Maxilla ( Fig. 10 C) movable endite outer margin with several setules, movable endite outer lobe with four distal and two subdistal setae; movable endite inner lobe with eight setae; outer lobe of fixed endite with eight distal setae, five multifurcate spiniform setae, and one serrated spine, outer margin with fine denticles; inner lobe of fixed endite with row of 18 setae and four long pinnate setae. Maxilliped ( Fig. 10 D) coxa short; basis naked; endite inner margin with three coupling hooks and several setae, distal margin with six multiform setae ( Fig. 10 E), two pinnate setae and five simple setae; palp article 1 naked, article 2 with 13 inner setae and one plumose seta at the outer distal corner, articles 3 and 4 both with seven distal setae. Epignath ( Fig. 10 F) cup-shaped, with one distal seta.

Cheliped ( Fig. 11 A) exopod ( Fig. 11 B) present, three-articled, distal article with three plumose setae; basis about twice as long as wide, dorsal margin with two large proximal plumose setae, three simple setae, and rows of irregular-sized denticles, ventral margin with three broom setae, distoventral margin with one strong apophysis and seven plumose setae; merus with one strong ventral apophysis and two broom setae; carpus long, two times as long as basis, with several broom setae, one distodorsal apophysis, one proximoventral and one distoventral apophysis; propodus (including fixed finger) about 0.65 times as long as carpus, with 13 simple setae on ventral, distal and incisive margins; dactylus 0.5 times as long as propodus, with five simple setae on incisive margin and two broom setae on dorsal margin.

Pereopods all thin, stick-like. Pereopod 1 ( Fig. 11 C) exopod absent; coxa with prominent apophysis and three adjacent plumose setae; basis dorsal margin with eight pointed apophyses and more than eight plumose setae, ventral margin with about nine plumose setae; ischium with three plumose setae; merus with four plumose setae and three simple setae; carpus with five distodorsal setae, six lateral spines, and seven ventral spines; propodus dorsal margin with one simple and one broom setae, three distal pinnate setae, and one distal spine, distal margin with four simple setae, ventral margin with five lateral and six marginal spines; dactylus with two dorsal setae, one ventral seta, and one ventral process near unguis. Pereopod 2 ( Fig. 11 D) similar to pereopod 1, but coxa without plumose setae, basis with more plumose setae and five dorsal pointed apophyses, carpus with five lateral spines, propodus without serrated setae. Pereopod 3 ( Fig. 11 E) similar to pereopod 2 but basis with four dorsal apophyses and few plumose setae, ischium with one plumose setae, merus with three plumose setae, carpus with four lateral and five ventral spines, propodus with three dorsal broom setae and four ventral lateral spines. Pereopod 4 ( Fig. 12 A) coxa without apophyses or setae; basis with four dorsal broom setae, three dorsal apophyses, seven plumose setae on dorsal and nine plumose setae on ventral margin; ischium with one ventral seta; merus with three dorsal plumose setae, two ventral setae, and one distoventral spine; carpus with two dorsal, three lateral and two ventral setae, and one distoventral spine; propodus with one simple seta and two broom setae on dorsal margin, ventral margin with three spines and two setae, distal margin with eight strong pinnate setae; dactylus with one ventral process. Pereopod 5 ( Fig. 12 B) coxa without apophyses, with one short seta; basis dorsal margin with three broom setae, four apophyses, and six plumose setae, ventral margin with eight plumose setae; ischium with two ventral setae; merus with one dorsal plumose seta, one plumose distoventral seta and one simple distoventral setae; carpus with one plumose seta and three simple setae; propodus with one dorsal seta, one simple, one plumose and one broom distodorsal seta, ventral margin with five simple setae and one lateral seta; dactylus with one ventral process. Pereopod 6 ( Fig. 12 C) similar to pereopod 5 but basis dorsal margin with two apophyses and eight plumose setae, ischium with two dorsal plumose setae; carpus with eight simple setae, propodus without plumose setae, and ventral margin with five spines.

Pleopod ( Fig. 9 D) only on pleonites 4–5, reduced and uniramous, with one distal simple seta.

Uropod ( Fig. 12 D) basis with two distal setae; exopod three-segmented, with two distal setae; endopod eightsegmented, with many setules, segment 2 with two broom setae and one simple distal seta, segment 3 with one distal seta, segment 4 with three distal setae, segment 5 with one distal seta, segment 6 with three distal setae, segment 7 without setae, and segment 8 with five distal setae.

Etymology. The name is derived from the Latin “ multi ” (many) and “ tuberculata ” (tubercles), referring to the presence of many tubercles terminally on pleotelson in described species. Type locality. Jihuei, eastern Taiwan.

Distribution. It is only known from the type locality.

Remarks. The present species, Indoapseudes multituberculata sp. nov., is undoubtedly morphologically different from its currently known congeners. Table 3 shows that I. multituberculata has only few morphological characters that are similar to any other Indoapseudes species (Table 3). Moreover, it has three unique morphological characters which are not seen in the other species: 1) females having two pairs of pleopods (on pleonites 4–5), 2) the pleotelson with many apical tubercles, 3) mandible palp article 1 with noticeable distal teeth ( Fig. 9 D–E; Table 3).

Figures

FIGURE 9. Indoapseudes multituberculata sp. nov. Holotype (NMNS 7342 - 1) female: A body dorsal view; B right antennule; C left antenna; D pleon; E left mandible; F right mandible incisor and setal row. Scale: A, 1 mm; B – F, 0.1 mm.

FIGURE 10. Indoapseudes multituberculata sp. nov. Holotype (NMNS 7342 - 1) female: A left half of labium; B right maxillule; C maxilla; D right maxilliped; E right maxilliped endite distal spiniform setae; F epignath. Scale: A – F, 0.1 mm.

FIGURE 11. Indoapseudes multituberculata sp. nov. Holotype (NMNS 7342 - 1) female: A left cheliped; B paratype female (NMNS 7341 - 2), right cheliped exopod; C – E left pereopods 1 – 3, respectively. Scale: A – D, 0.1 mm.

FIGURE 12. Indoapseudes multituberculata sp. nov. Holotype (NMNS 7342 - 1) female: A right pereopod 4; B – C left pereopods 5 – 6, respectively; D paratype female (NMNS 7341 - 2), left uropod. Scale: A – D, 0.1 mm.