Calozodion dominiki, 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 : 45-49

Calozodion dominiki sp. nov.

Figs. 8–10

Type material. Holotype: adult male, 2.7 mm; partially dissected (St. 29: grab and dredge sampling; 17° 23.415Ś 11°43.432´E) [ ZMB 28049]; Paratypes: 20 males, 20 females, (same data as holotype [ ZMB 28049].

Further material. 1 juvenile 1.3 mm (St. 2: grab sampling; 7° 14.186Ś 12°46.025´E); 1 ovigerious female, 2.8 mm, (St. 4: dredge sampling; 9° 04.894Ś 12°56.063´E); 64 specimens 2.0– 3.4 mm, (St. 7: dredge sampling; 9° 33.703Ś 13°06.020´E); 7 specimens 2.4–2.8 mm (St. 12: grab sampling; 13° 57.670Ś 12°21.870´E); 11 specimens 2.1–3.5 mm; 1 male 2.6 mm; 1 brooding female 3.1 mm (St. 13: grab sampling; 15° 00.048Ś 12°07.685´E); 60 specimens (St. 14: grab sampling; 15° 10.834Ś 12°04.920´E); 27 specimens (St. 15: grab and dredge sampling; 15° 17.559Ś 12°00.031´E); 79 specimens 2.0– 3.4 mm, (St. 23: grab and dredge sampling; 17° 18.946Ś 11°43.389´E); 244 specimens (St. 29: grab and dredge sampling; 17° 23.415Ś 11°43.432´E); 107 specimens (St. 32: grab sampling; 17° 57.633Ś 11°46.104´E); 88 specimens 2.1–3.4 mm (St. 33: grab and dredge sampling; 18° 11.444Ś 11°50.475´E); 54 specimens 2.0– 3.5 mm (St. 34: grab and dredge sampling; 18° 23.116Ś 11°55.289´E); 53 specimens (St. 35: dredge sampling; 8° 45.320Ś 13°12.890´E); 8 specimens 2.4–2.8 mm (St. 36: grab sampling; 17°00.988´S; 11° 27.478É); 2 males 3.5 (St. 38: grab and dredge sampling; 17°23.416´S; 11° 42.226É).

Description of the male. Body ( Fig. 8 A) dorso-ventrally flattened, small (length of holotype 2.7 mm), approximately 5.2 times as long as width of carapace. Cephalothorax longer than wide, with prominent rostrum, slightly downturned, eyelobes conspicuous, with visual elements. Pereonites 1 to 6 respectively 0.36, 0.43, 0.55, 0.5, 0.58 and 0.45 times as long as wide, pereonites 2, 3 and 6 laterally convex, pereonites 4 and 5 trapezoidal, with lateral plumose setae, pereonite 6 with antero-dorsal plumose setae, pereonites four and five with a tuberculiform process in the first half, antero-laterally. Pleon with five free pleonites each five to six times as wide as long, with dorsal and lateral plumose setae. Pleotelson short, with prominent processes “shoulders” laterally and at uropod insertion, distally rounded, with plumose setae laterally and antero-dorsally.

Antennule. ( Fig. 8 C) Peduncle article 1 elongate, with one conspicuous inner process; second article one quarter as long as first; third article shorter and thinner than second. Accessory flagellum with two and main flagellum with nine articles, single aesthetascs on articles 4, 6 and 8.

Antenna. ( Fig. 8 E) With five-articled peduncle, first article short, with prominent inner expansion bearing plumose setae; second peduncle article long, longer than following two articles together, with two denticles, one of them very small, proximally, bearing short squama with three long setae, with plumose seta on inner margin, fourth and fifth articles subequal; flagellum of five articles.

Mouthparts. Mandibles ( Fig. 9 B, C) typical of the genus, with three-articulated palp bearing long setae on all articles. Labium ( Fig. 9 A) denticulate on lateral margin; terminal lobe (palp) with single distal seta, densely setose on inner side, with few setae on outer side, with one small proximal process. Maxillule ( Fig. 9 D) inner lobe with four distal setae and projecting outer margin; both lobes with finely setose margins; palp with two articles, second article has a long setulose seta. Maxilla ( Fig. 9 E) outer lobe of movable endite with two denticles and fine setae on outer margin, distally with two strong pinnate setae and three finely-denticulate setae, and inner lobes denticulate; outer lobe of movable endite distal with five plumose setae and three trifurcate spines, with two plumose setae on inner margin; fixed endite with outer margin denticulate, with one plumose setae and a row of about 15 setae. Maxilliped ( Fig. 9 F) basis with some small and acute projections antero-laterally; palp with four articles, with numerous long simple and plumose setae on inner margins; first article with simple setae anterior on inner and outer margin; second article with one strong plumose seta subterminally; endite with two couplers. Epignath ( Fig. 9 G) broad with terminal spine.

Cheliped. ( Fig. 9 H) Robust and relatively short, with short simple and plumose setae as figured; exopodite present; basis short and wide, with plumose setae on the dorsal side, with single blunt spine antero-ventally; merus small; carpus short and wide; propodus very large, with three to four small processes proximo-ventrally, fixed finger with four tooth-like apophyses, unguis strong; dactylus strong with one apophysis ventrally, unguis strong.

Pereopod 1. ( Fig. 10 A) With exopodite; with strong basis, having several spine-like processes altering with long plumose setae dorsally, with single short spine sterno-distally; ischium short; merus longer than carpus or propodus, with simple and plumose setae, with a short strong spine antero-ventrally and long strong spine distodorsally; carpus wide, with strong plumose setae dorsally, distal with two strong spines ventrally and dorsally; propodus longer and thinner than carpus, with three strong spines increasing in size interspersed with plumose setae ventrally, with one strong spine dorso-distally; dactylus strong, shorter than propodus, with two setae dorsal and ventral; unguis stout, rounded terminally.

Pereopod 2. ( Fig. 10 C) Basis long and slender, with dorsal process; ischium short; merus and carpus subequal in size, each with blunt ventral spine; propodus as long as merus and carpus together, slightly recurved, with four spines ventrally and one spine antero-distally; dactylus strong, recurved, unguis long and acute, dactylus and unguis together shorter than propodus.

Pereopod 3. ( Fig. 10 D) Similar to pereopod 2, dorsal process of basis spine-like.

Pereopod 4. ( Fig. 10 E) Basis long, without special features; ischium short; merus with paired ventral blunt spines; carpus ventral with one single and a pair of blunt spines, distal with pair of dorsal blunt spine; propodus of same length as carpus, with finely hairy distal setae above dactylus, dactylus plus unguis shorter than propodus; dactylus thin; unguis curved.

Pereopod 5. ( Fig. 10 F) Basis and ischium similar to pereopod 4; merus of same length than propodus, with single plumose dorsal setae, with single short ventral distal spine; carpus shorter than merus, with single plumose dorsal seta, with one single and two pairs ventral stout spines; propodus with pair ventral blunt spines; dactylus long and thin, dactylus plus unguis shorter than propodus; unguis curved, acute.

Pereopod 6. ( Fig. 10 G) Basis with ventral and dorsal long plumose setae; merus longer than carpus, but approximately equal with propodus, with ventral and dorsal short plumose setae, carpus with few short plumose setae and short simple ventral seta; propodus with a row of about 16 short setae disto-ventrally, with a row of nine longer finely denticulate distal setae, dactylus stronger than dactylus of pereopod 5, recurved; unguis strong, acute.

Pleopods. ( Fig. 10 H) Biramous; in five pairs; rami uniarticulate, with plumose setae; endopodite shorter than exopodite, both long and thin.

Uropods. ( Fig. 10 I) Biramous; basis exceeding distal tip of telson, with six plumose setae on inner margin, with one plumose seta distal on outer margin; exopodite three-articled and endopodite with 15 articles.

Female. Similar to the male except for cephalothorax, antennule, antenna, cheliped and pereopod 1; cephalothorax ( Fig. 8 B) with short rounded rostrum; antennule ( Fig. 8 D) more robust than that of male, basis with two apophyses on inner and outer margin, main flagellum with seven articles, single aesthetascs on articles 3 and 5, antenna ( Fig. 8 F) flagellum with four articles; antenna shorter than in male, articles 2, 4 and 5 subequal, article 1 with apophysis, distal margin denticulate, article 2 with two apophyses on inner side, proximal and distal and two small denticles antero-laterally, cheliped ( Fig. 9 I) merus and carpus longer and propodus smaller than those of male, propodus only little longer than carpus and only little broader than distal part of carpus, merus and carpus with single ventral spine, propodus with single spine mid-ventrally; pereopod 1 ( Fig. 10 B) propodus shorter than in male.

Etymology: The new species is named after Dominik Bochert, son of the author.

Variability. A morphological feature with a strong variability consists in the shape of the male rostrum. Males have a prominent rostrum and females build only short rounded rostrum. The rostrum in males could be shorter than in the holotype and greatest variability exists in the degree to which it is turned down. The rostrum could be only slightly downturned, like in holotype, but in cases of specimens with a strongly downturned rostrum, the typical rostral tip is lacking and its distal part appears truncated from dorsal view.

Remarks. Previously nine species were known within the genus. They are distributed in the Atlantic and also in the Indian Ocean, but most species are known from the Northwest Atlantic ( Gardiner, 1973, Gutu, 1984, 2002), and two species were found off Brazil ( Gutu, 1996). Calozodion simile Gutu, 2006 alone is described off North West Africa ( Mauritania).

Calozodion dominiki sp. nov. males are readily distinguished from all other known males (seven species) of this genus in that the cheliped propodus fixed finger has only small processes proximo-ventrally, in the bases of pereopods 2 and 3 having a dorsal process, in the shape of the rostrum and in the shape of first peduncle article of the antennules.

C. dominiki is very similar to C. simile and C. wadei Gardiner, 1973 in having pereopod 2 and 3 basis with a dorsal process, whereas all other species lack these features, and Calozodion suluk Bamber & Sheader, 2005 has a process on basis of pereopod 2 only. The new species differs from C. simile by the first peduncle article of antennules lacking two large spiniform apophyses, in lacking plumose setae on the inner margin and in lacking four spiniform apophyses and plumose setae on the outer side. The new species differs from C. wadei by the absence of stout spines on the male cheliped propodus.

Males are not known for the following two species, and Calozodion dominiki is distinguished from Calozodion dollfusi Gutu, 1989 in the shape of the rostrum and in the shape of first peduncle article of antennules, and from Calozodion heardi Gutu, 2002 in the shape of the pleotelson and in the shape of the cheliped.

Distribution. West Africa: Off Angola and off North Namibia from 7°– 18.5° S; 20–117 m water depth.

Figures

FIGURE 8. Calozodion dominiki sp. nov. A, male dorsal; B, female dorsal; C, antennule male; D, antennule female; E, antenna male; F, antenna female.

FIGURE 9. Calozodion dominiki sp. nov. male A, labium; B, left mandible; C, right mandible (palp not shown); D, maxillule; E, maxilla; F, maxilliped; G, epignath; H, cheliped male; I, cheliped female.

FIGURE 10. Calozodion dominiki sp. nov. A, pereopod 1 male; B, pereopod 1 female; C, pereopod 2 male; D, pereopod 3 male; E, pereopod 4 male; F pereopod 5 male; G, pereopod 6 male; H, pleopods 1 male; I, uropod male.