Apseudopsis cuanzanus, Bochert, Ralf, 2012

Bochert, Ralf, 2012, Apseudomorph Tanaidacea from the continental shelf of Angola and Namibia with descriptions of three new species, Zootaxa 3583, pp. 31-50 : 35-39

publication ID	https://doi.org/ 10.5281/zenodo.209551
publication LSID	lsid:zoobank.org:pub:F220EF0F-0F9B-44B6-B349-22A1651E8FD6
DOI	https://doi.org/10.5281/zenodo.5659816
persistent identifier	https://treatment.plazi.org/id/D2324A76-1439-B342-FF2A-FF3C6C47F827
treatment provided by	Plazi
scientific name	Apseudopsis cuanzanus
status	sp. nov.

Treatment

Apseudopsis cuanzanus View in CoL sp. nov.

Figs. 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4

Type material. Holotype: female, 4.5 mm (St. 6: grab sampling; 9°26.000´S, 12°59.974´E) [ ZMB 28051]; Paratype: one female, 3.3 mm (same data as holotype) [ ZMB 28051].

Description of the female. Body ( Fig. 2 View FIGURE 2 A) dorso-ventrally flattened, small (length of holotype 4.5 mm), slender, about 7 times as long as wide. Cephalothorax slightly longer than wide, with long and acute rostrum, median sides of rostrum with small shoulders, naked; ocular lobes well developed, acute, with sparse ocelli. Pereonite 1 shortest, pereonites 2 and 6 of same length, pereonites 3 to 5 of about same length, pereonites 1 to 6 respectively 0.46, 0.56, 0.81, 0.77, 0.84 and 0.54 times as long as wide, pereonites 3 to 5 with a small lobate expansion antero-laterally, all pereonites with a hook-like process postero-laterally, pereonite 1 naked, all other pereonites with few setae antero-laterally and postero-laterally; ventrally, pereonites two and six with well developed hyposphaenia ( Fig. 2 View FIGURE 2 B). Pleon with five short and wide, free pleonites, all pleonites extended posterolaterally into spine-like projection, all pleonites with plumose setae laterally. Pleotelson longer than wide, with one swelling on each side, medio-laterally, distally rounded, with few setae medio-laterally and dorsally.

Antennule. ( Fig. 2 View FIGURE 2 C) Peduncle article 1 elongate, sparsely setose, articles 1 and 2 each with row of setae subdistally, accessory flagellum with three, and main flagellum with seven articles, single aesthetascs distally on articles 3 and 5.

Antenna. ( Fig. 2 View FIGURE 2 D) Peduncle first article with prominent inner apophysis, with one small seta, distal margin slightly serrate; second peduncle article as long as fifth article, with squama bearing eleven setae marginally and distally, squama as long as article 5; flagellum of six articles.

Mouthparts. Mandibles ( Fig. 2 View FIGURE 2 E, F) with three articulated palp, all articles subequal, article 1 with five pairs of long setae on inner anterior margin, article 2 with four short setae subdistally, article 3 with five long setae anterolaterally and distally; pars incisiva of both mandibles with four denticles; setiferous lobe of the left mandible with four bi-or tri-furcate setae, setiferous lobe of the right mandible with three bi-or tri-furcate setae, with three serrate setae and one simple seta; lacina mobilis only on left mandible, with four denticles; pars molaris thick. Maxillule ( Fig. 2 View FIGURE 2 G) with biarticulate palp, article 1 slightly longer than article 2, with four long setae terminally, inner lobe with six plumose setae distally, outer margin with small apophysis and setose; outer lobe with eleven spines distally; outer margin densely setose anteriorly, slightly serrate. Maxilla ( Fig. 2 View FIGURE 2 H) outer lobe of movable endite with fine setae on outer margin, serrate, inner and outer lobes of movable endite with finely-denticulate and plumose setae; fixed endite with three trifurcate spines, one plumose and several denticulate setae; fixed endite inner margin with prominent denticulation, with row of simple setae and few plumose setae. Maxilliped ( Fig. 2 View FIGURE 2 I) basis robust; palp with four articles; first article with single seta on inner and outer distal margin; second article longest, broad, with row of ten long simple setae mid-ventrally, with row and pairs of about 17 simple setae anterolaterally and eight setae distally, with long single seta on inner and outer distal margin; third article little longer than fourth, broad, six pairs of simple setae antero-laterally, fourth article with seven setae distally; endite with four couplers, with nine plumose setae on inner side, with ten curved setae distally and one simple seta subterminally. Epignath ( Fig. 2 View FIGURE 2 J) large, broad, with simple seta.

Cheliped. ( Fig. 3 View FIGURE 3 A) Robust and relatively long, with tri-articulate exopodite, article 3 short bearing four plumose setae; basis short and wide, with one spine mid-ventrally, with row of five simple setae on dorsal side; merus slender, only slightly shorter than basis, with few simple setae distally and three setae mid-laterally; carpus long, elongate, with several simple setae on ventral margin, with three rows of three to five setae proximo-dorsally, with simple setae distally and subterminally; propodus robust, shorter than carpus, nearly twice as long as wide, inner margin with short setae and short spines, claw strong; dactylus strong, long, dorsally with three fine simple setae, cutting edge naked, unguis strong, stout.

Pereopod 1. ( Fig. 3 View FIGURE 3 B) With tri-articulate exopodite, article 3 short bearing four plumose setae; coxa spiniform distally and with acute hook-like process proximally; basis broad, about twice as long as wide, with short distal spine, with several short simple setae; ischium short; merus robust, distally dilated, with single spine anteroventrally, ventral and dorsal margin with three to four setae; carpus shorter than merus, with dorsal row of nine simple setae and one strong, long, acute spine distally, with two strong spines ventrally accompanied by short simple setae; propodus shorter than carpus, with three simple setae and two spines distodorsally, with five long, robust spines ventrally; dactylus short, robust, with single distal seta, unguis short, acute.

Pereopod 2. ( Fig. 3 View FIGURE 3 C) Basis long, with brush of six setae distally; ischium short; merus robust, slightly shorter than carpus, dilated distally, with nine simple setae and single strong spine on ventral margin; carpus more or less rectangular, with seven simple setae and single long spine on ventral margin, with three long simple setae middorsally, with five long and five short simple setae distally and subterminally on dorsal margin; propodus about as long as carpus, ventral margin crenulated, with eight simple setae, with about ten long and short simple setae distally and subterminally on dorsal margin; dactylus slender, without distal seta, unguis small, acute.

Pereopod 3. ( Fig. 3 View FIGURE 3 D) Basis long and slender; merus with about 5 setae on ventral margin, one slender spine distally, row of four setae antero-laterally; carpus with six setae and one slender spine ventrally, with row of about eleven setae on inner side; propodus shorter than carpus, with six setae and one slender spine ventrally, with single and pairs of simple setae on inner side, dorsal with two setae distal and single broom seta proximal; dactylus about as long as propodus, robust, without distal seta, unguis acute.

Pereopod 4. ( Fig. 4 View FIGURE 4 A) Basis long, with single broom seta on dorsal margin; merus short, with setae ventrally; carpus long, about three times as long as wide, with about eight pairs of simple setae on ventral margin, with row of four setae subterminally; propodus long, shorter than carpus, with broom seta proximo-dorsally, with simple setae ventrally, with rows of about twelve longer and fourteen short serrate setae distally; dactylus short and slender, without distal seta, inconspicuous.

Pereopod 5. ( Fig. 4 View FIGURE 4 B) Similar to pereopod 4; basis with two and propodus with single broom setae; carpus with about twelve setae, ventrally and distally; propodus with distal process, with single long, slender spine, ventrally, with row of six short setae and with three longer simple setae, with five short serrate setae, with four long setae terminally; dactylus long and slender, without distal seta, unguis acute.

Pereopod 6. ( Fig. 4 View FIGURE 4 C) Basis robust, with simple setae on ventral margin; merus about as long as propodus, robust, with four long plumose setae dorsally and eight simple setae ventrally; carpus slightly longer than merus and propodus, with row of nine setae on ventral margin and seven plumose setae dorsally; propodus with one short spine proximo-ventrally, with row of about 27 setae ventrally and distally; dactylus long and slender, slightly longer than propodus, with short seta distally, unguis long, acute.

Pleopods. ( Fig. 4 View FIGURE 4 D) Biramous; in five pairs; basal article short and thick, with long plumose setae on both margins; rami uniarticulate, with long plumose setae; endopodite slightly shorter than exopodite.

Uropods. ( Fig. 4 View FIGURE 4 E) Biramous; basis short, exceeding distal tip of telson, with two short setae distally; exopodite with three articles and endopodite with 30 articles, with single and pairs of broom setae on articles 15, 20 and 25.

Male. Unknown.

Etymology. After the name of the Angolan river Cuanza, which empties near the type locality at 9°20’ S into the Atlantic Ocean.

Remarks. Until now, 20 species were known within the genus Apseudopsis ( Esquete et al., 2012) . The main differentiating characteristics are the presence of a dorsodistal spine on the pereopod 1 merus, of anterolateral spines on the pereonites, the shape of the rostrum and the occurrence of plumose setae on the pereopod six basis. Apseudopsis cuanzanus sp. nov. is immediately distinguished by the shape of the rostrum from Apseudopsis tridens ( Gutu, 2002) (tridentate), Apseudopsis erythraeicus ( Bacescu, 1984) (short triangular) and Apseudopsis minimus ( Gutu, 2002) (with two rounded lobes at base). The new species is separated from Apseudopsis olimpiae ( Gutu, 1986) , Apseudopsis latreilli ( Milne-Edwards, 1828) , Apseudopsis elisae ( Bäcescu, 1961) , Apseudopsis robustus ( Sars, 1882) and Apseudopsis bruneinigma ( Bamber, 1998) because they have a dorsodistal spine on the pereopod 1 merus. Further, Apseudopsis hastifrons ( Norman & Stebbing, 1886) and Apseudopsis acutifrons ( Sars, 1882) have anterolateral spines on their pereonites, which distinguish them from A. cuanzanus .