SYSTEMATICS

Suborder APSEUDOMORPHA Sieg, 1980
Superfamily APSEUDOIDEA Leach, 1813
Family APSEUDIDAE Leach, 1813
Subfamily LEVIAPSEUDINAE Sieg, Reference Sieg, Gruner and Holthuis1983
Genus Fageapseudes Băcescu & Guţu, 1971
Fageapseudes bicornis (Kudinova-Pasternak, Reference Kudinova-Pasternak1973)
(Figures 1–3)

Apseudes bicornis Kudinova-Pasternak, Reference Kudinova-Pasternak1973, pp. 143–146; Fageapseudes bicornis Băcescu, Reference Băcescu1978, p. 200; Collosella bicornis Jóźwiak & Błażewicz-Paszkowycz, Reference Jóźwiak and Błażewicz-Paszkowycz2007, pp. 8, 14.

Fig. 1.

Fageapseudes bicornis (Kudinova-Pasternak, Reference Kudinova-Pasternak1973), neotype female: (A) lateral view; (B) dorsal view. Scale bar: 5 mm.

Fig. 2.

Fageapseudes bicornis (Kudinova-Pasternak, Reference Kudinova-Pasternak1973), female: (A) antennule; (B) antenna; (C) left mandible; (D) right mandible; (E) mandibular palp; (F) labium; (G) maxillule; (H) maxilla; (I) maxilliped; (J) maxillipedal endites. Scale bars: A–F and H–J, 0.2 mm; G, 0.1 mm.

Fig. 3.

Fageapseudes bicornis (Kudinova-Pasternak, Reference Kudinova-Pasternak1973), female: (A) cheliped; (B) pereopod-1; (C) pereopod-2; (D) pereopod-3; (E) pereopod-4; (F) pereopod-5; (G) pereopod-6; (H) pleopod. Scale bars: 0.2 mm.

MATERIAL EXAMINED

Neotype female (drawn in Figure 1), 12 mm long, (So 223, Station 1–10; coordinates: 43°58.26′–43°58.33′N 157°19.68′–157°17.98′E, EBS; water depth: 5417–5423 m) (cat. no. ZMH K-44336) 30 July 2012.

Additional material: one specimen (dissected on slides) (So 223, Station 6–11; coordinates: 42°29.58′–42°28.47′N 154°0.04′–153°59.67′E, EBS-S; water depth: 5290–5305 m) (cat. no. ZMH K-44337) 15 August 2012; one specimen (So 223, Station 6–11; coordinates: 42°29.58′–42°28.47′N 154°0.04′–153°59.67′E, EBS-S; water depth: 5290–5305 m) 15 August 2012; one specimen (So 223, Station 2–10; coordinates: 46°13.54′–46°14.99′N 155°33.58′–155°32.64′E, EBS-S; water depth: 4857–4867 m) 3 Aug 2012; two specimens (So 223, Station 2–9; coordinates: 46°13.60′–46°14.93′N 155°33.42′–155°32.57′E, EBS; water depth: 4860–4866 m) 2 August 2012; one specimen (So 223, Station 3–9; coordinates: 47°13.83′–47°14.87′N 154°41.88′–154°43.18′E, EBS-S; water depth: 4988–4998 m) 5 August 2012; two specimens (So 223, Station 5–9; coordinates: 43°35.50′–43°34.30′N 153°57.89′–153°58.18′E, EBS-S; water depth: 5376–5378 m) 11 August 2012; one specimen (So 223, Station 6–12; coordinates: 42°29.47′–42°28.20′N 153°59.93′–153°59.73′E, EBS-S; water depth: 5290–5307 m) 15 August 2012.

DIAGNOSIS

Pleonites without lateral apophyses and ventral bulbus, mandibles body with crenulated outer margin, article-2 of mandibular palp about 10 times as long as wide, labial palp with one spine, cheliped basis without ventral spine, cheliped propodus with three dorsal subdistal long setae, and dactylus of pereopod-4 simple.

DESCRIPTION

Female. Body (Figure 1A, B) elongated, 12 times as long as wide. Carapace without rostrum, distinctly wider in distal part; eyelobes well developed, acute and fused to carapace, visual elements absent. Pereon of six free pereonites; pereonite-1 smooth laterally, remaining pereonites with well developed lateral apophyses and hyposphenium, pereonites length-width ratio 0.6, 1.6, 2.1, 2.6, 2.3 and 2.3 respectively. Pleon of five free pleonites; pleonites trapezoidal, without lateral apophyses, subequal in length.

Antennule (Figure 2A) peduncle article-1 10 times as long as wide, with four simple setae on inner margin and one simple and seven penicillate setae on outer margin; article-2 about half as long as article-1, with one simple seta on inner margin and one simple and four penicillate setae subdistally; article-3 0.6 times as long as article-2, with three minute setae distally; article-4 with single distal seta. Outer flagellum with eight segments, with usually pair of simple distal setae; segments 4, 5 and 7 with aesthetasc; last segment with six simple setae of varying length. Inner flagellum with two unequal segments; segment-1 with one simple seta and segment-2 with three setae distally.

Antenna (Figure 2B) peduncle article-1 with distal inner projection; article-2 4.4 times as long as wide, with one inner seta; squama elongated, with two simple setae distally; article-3 about 0.3 times as long as article-2, with one simple seta on inner margin; article-4 2.7 times as long as article-3, with two subdistal penicillate setae; article-5 subequal to article-4, with six penicillate setae distally and subdistally. Flagellum of five segments, that bears usually pair of distal setae; segment-2 seta reaches end of last article; segment-5 with four distal setae of varying length.

Mouthparts. Left mandible (Figure 2C) body slightly crenulated on outer margin and with few simple setae distally; incisor well calcified, with five small denticles; lacinia mobilis with five denticles; setiferous lobe with seven multifurcated setae; molar wide and strongly calcified. Right mandible (Figure 2D) incisor bifurcated; setiferous lobe with one simple and five multifurcated setae; molar with numerous minute setae. Palp (Figure 2E) of three articles; article-1 with one simple seta on inner margin; article-2 about 10 times as long as wide, with three long simple and seven serrated setae on inner margin; article-3 with two rows of serrated setae and one simple seta on inner margin. Labium (Figure 2F) with small denticles on outer margin and setation on inner margin; palp narrow covered with setae, distally with one spine. Maxillule (Figure 2G) inner endite with four distal spines, at least two of them plumose; outer endite with pair of simple setae subdistally and 11 spines distally, outer margin with numerous simple setae. Maxilla (Figure 2H) outer lobe of moveable endite with two plumose setae subdistally and one plumose and four simple setae distally; inner lobe of moveable endite with seven plumose setae; outer lobe of fixed endite with four simple, two (one broken) plumose and three multifurcated setae; inner lobe of fixed endite with row of at least 20 setae and one thick plumose seta. Maxilliped (Figure 2I) basis with two inner setae; palp article-1 with one inner and one outer seta; article-2 with one outer distal seta and with inner row of at least 17 simple and plumose setae; article-3 with three simple setae on inner margin; last article with six distal setae, two of them slightly serrated. Endites (Figure 2J) inner margin with four to six coupling hooks and four to six plumose setae; distal margin with bi- and multifurcated setae, caudoinner seta slim leaflike.

Cheliped (Figure 3A) basis with four short setae ventrally and tubercle distally; exopod of three articles, last article with three distal setae (one broken); merus with one dorsal and three ventral short simple setae; carpus about twice as long as merus, with two long dorsal and six long ventral setae; propodus 1.1 times as long as wide, with five setae on dorsal margin and three setae near dactylus insertion; fixed finger as long as propodus, with four ventral setae, cutting edge with strong tooth and row of serrated denticles; dactylus subequal to fixed finger, with three dorsal setae and denticles on cutting edge.

Pereopod-1 (Figure 3B) basis four times as long as wide, with one penicillate seta on ventral and dorsal margins, ventrodistally with single simple seta, subdistally with tubercle; ischium with one simple seta and tubercle; merus about half as long as basis, with two rows of simple setae: one dorsally and one ventrally; carpus 0.6 times as long as merus, with row of simple setae and single spine on dorsal and ventral margins; propodus 0.7 times as long as carpus, with three simple setae and two spines dorsally and three simple setae and six spines ventrally; dactylus with three ventral denticles, dactylus and unguis 0.9 times as long as propodus, dactylus longer than unguis.

Pereopod-2 (Figure 3C) basis 5.7 times as long as wide, with one ventrodistal seta; ischium apparently naked; merus 0.3 times as long as basis, with one dorsodistal simple seta; carpus half as long as basis, with row of ventral setae and six simple setae dorsodistally; propodus 0.6 times as long as carpus, with apparently one serrated and eight simple setae ventrally (some of them broken off) and one spine and five setae dorsally; dactylus broken.

Pereopod-3 (Figure 3D) similar to pereopod-2, but basis with three penicillate setae ventrally, ischium with seta, merus with two subdistal ventral setae, propodus with dorsal penicillate seta.

Pereopod-4 (Figure 3E) basis about six times as long as wide, with three penicillate setae dorsally; ischium naked; merus 0.2 times as long as basis, with one dorsodistal seta; carpus 2.3 times as long as merus, with eight setae distally; propodus 0.6 times as long as carpus, with one long seta ventrally, one penicillate seta dorsally and nine simple and four serrated setae distally; dactylus with single dorsal seta, dactylus and unguis shorter than some of propodus distal setae.

Pereopod-5 (Figure 3F) similar to pereopod-4, but carpus with 13 setae distally in two rows, propodus with row of serrated setae ventrally and only four distal setae, dactylus with distal short seta, dactylus and unguis longer than propodus setae.

Pereopod-6 (Figure 3G) similar to pereopod-5, but basis without penicillate setae, carpus with less setae and dactylus with dorsal seta.

Pleopod (Figure 3H) basis elongated, 7.4 times as long as wide; exopod uniarticled, with plumose seta at the midlength and two setae distally; endopod of two articles, article-1 0.4 times as long as article-2, naked; article-2 with two setae distally.

Uropods broken.

REMARKS

From six currently known Fageapseudes species, F. bicornis closely resembles F. suprema (Jóźwiak & Błażewicz-Paszkowycz, Reference Jóźwiak and Błażewicz-Paszkowycz2007) by having only one spine on labial palp, by lacking lateral apophyses on pleonites and by lacking spine ventrally on cheliped basis and denticles on pereopod-4 dactylus. Those similarities may in fact suggest that both species are members of a new genus as was already proposed for F. suprema by Jóźwiak and Błażewicz-Paszkowycz (Reference Jóźwiak and Błażewicz-Paszkowycz2007); although F. bicornis can be distinguished from F. suprema by having mandibles body with crenulated outer margin, article-2 of mandibular palp about 10 times as long as wide and three long setae dorsally on cheliped propodus (near dactylus insertion). Fageapseudes suprema has a smooth outer margin of mandibles body, article-2 of mandibular palp five times as long as wide and only two minute setae on the top of cheliped propodus.

There are slight differences between the description of F. bicornis from the current study and that presented by Kudinova-Pasternak (Reference Kudinova-Pasternak1973):

• • length/width ratio of article-3 of maxillipedal palp: it is 1.0 in Kudinova-Pasternak (Reference Kudinova-Pasternak1973) and 0.6 in this study;

• • length/width ratio of pereopod-1 carpus: two times as long as wide in oryginal description and 1.2 times in present study;

• • number of dorsal spines on pereopod-1 propodus: one in Kudinova-Pasternak (Reference Kudinova-Pasternak1973) and two in this study.

DISTRIBUTION

This species was known so far from two stations from the Gulf of Alaska (incorrectly assigned to Sea of Okhotsk by Anderson, Reference Anderson2013) in a depth range from 3350 to 3620 m (Kudinova-Pasternak, Reference Kudinova-Pasternak1973). In our studies F. bicornis was recorded in a series of stations west of Kurile Islands in a depth range from 4860 to 5423 m.

Fageapseudes vitjazi (Kudinova-Pasternak, Reference Kudinova-Pasternak1970)
(Figures 4–7)

Apseudes vitjazi Kudinova-Pasternak, Reference Kudinova-Pasternak1970, pp. 342–344, 379; Fageapseudes vitjazi Jóźwiak, Reference Jóźwiak2014, p. 24.

Fig. 4.

Fageapseudes vitjazi (Kudinova-Pasternak, Reference Kudinova-Pasternak1970), neotype female: (A) lateral view; (B) dorsal view. Scale bar: 5 mm.

Fig. 5.

Fageapseudes vitjazi (Kudinova-Pasternak, Reference Kudinova-Pasternak1970), female: (A) antennule; (B) antenna; (C) right mandible; (D) left mandible; (E) molar process; (F) mandibular palp articles 1 and 2; (F’) mandibular palp article-3; (G) labium; (H) maxillule. Scale bars: A–B, 0.2 mm; C–H, 0.1 mm.

Fig. 6.

Fageapseudes vitjazi (Kudinova-Pasternak, Reference Kudinova-Pasternak1970), female: (A) maxilla; (B) maxilliped; (C) maxillipedal endite; (D) epignath; (E) cheliped; (F) pereopod-1. Scale bars: A–E, 0.2 mm; F, 0.5 mm.

Fig. 7.

Fageapseudes vitjazi (Kudinova-Pasternak, Reference Kudinova-Pasternak1970), female: (A) pereopod-2; (B) pereopod-3; (C) pereopod-4; (D) pereopod-5; (E) pereopod-6. Scale bars: 0.2 mm.

MATERIAL EXAMINED

Neotype female (drawn in Figure 4 and partly dissected – one slide), 21.5 mm long (So 223, Station 9–11; coordinates: 40°34.70′–40°34.45′N 151°0.14′–151°0.15′E, AGT; water depth: 5407–5408 m) (cat. no. ZMH K-44338) 24 August 2012.

Additional material: one specimen dissected on slides (So 223, Station 3–5; coordinates: 47°14.30′N 154°42.23′E, GKG; water depth: 4984 m) (cat. no. ZMH K-443394) 5 August 2012; one specimen (So 223, Station 9–12; coordinates: 40°35.40′–40°34.27′N 150°59.84′–150°59.00′E, EBS; water depth: 5389–5400 m) 24 August 2012; two specimens (So 223, Station 5–9; coordinates: 43°35.50′–43°34.30′N 153°57.89′–153°58.18′E, EBS; water depth: 5376–5378 m) 11 August 2012; one specimen (So 223, Station 3–4; coordinates: 47°14.32′–47°14.32′N 154°42.26′–154°42.26′E, GKG; water depth: 4982 m) 4 August 2012; one damaged specimen (So 223, Station 2–9; coordinates: 46°13.60′–46°14.93′N 155°33.42′–155°32.57′E, EBS; water depth: 4860–4866 m) 2 August 2012; one specimen (So 223, Station 2–10; coordinates: 46°13.54′–46°14.99′N 155°33.58′–155°32.64′E, EBS; water depth: 4857–4867 m) 3 August 2012.

DIAGNOSIS

Pereonites with short lateral apophyses, pleonites with well developed lateral apophyses and ventral bulbus, mandibles body with smooth outer margin, second article of mandibular palp five times as long as wide, labial palp with three spines, cheliped basis with ventral spine, pereopod-1 coxa apophysis short, and dactylus of all pereopods with ventral denticles.

DESCRIPTION

Female. Body (Figure 4A, B) 8.2 times as long as wide. Carapace 14% of total body length, without rostrum but with well developed acute eyelobes, no track of visual elements. Pereon of six free pereonites; pereonites length-width ratio: 0.4, 0.7, 0.9, 1.0, 1.1 and 1.0 respectively; pereonites from 2 to 6 with lateral apophyses. Pleon 38% of total body length, with five free pleonites; pleonites squareshaped, subequal in size, with lateral acute apophyses accompanied by ventral bulbus; pleotelson as long as last three pleonites.

Antennule (Figure 5A) peduncle article-1 8.5 times as long as wide, with one penicillate and one simple setae on inner margin and four simple and seven penicillate setae on outer margin; article-2 0.3 times as long as article-1, with five simple and four penicillate setae subdistally; article-3 0.7 times as long as article-2, with three setae distally; article-4 naked. Outer flagellum with at least 10 segments, segment-8 with aesthetasc. Inner flagellum of four segments; segment-2 with two simple and two penicillate setae, segment-3 with one penicillate seta and segment-4 with three simple setae distally.

Antenna (Figure 5B) peduncle article-1 with distaloinner projection; article-2 with one inner seta; squama elongated, with one seta subdistally and four simple setae distally; article-3 with one simple seta on distaloinner margin; article-4 as long as article-5, naked; article-5 with three penicillate and two simple setae distally. Flagellum of seven segments; segments 1 and 2 with elongated simple seta; last segment with four distal setae.

Mouthparts. Right mandible (Figure 5C) incisor with six denticles distally; setiferous lobe with three simple and four bifurcated setae. Left mandible (Figure 5D) incisor with six denticles distally; lacinia mobilis with four denticles; setiferous lobe with three simple and four bifurcated setae; molar process (Figure 5E) with numerous minute setae. Palp (Figure 5F, F’) of three articles; article-1 with single inner seta; article-2 five times as long as wide, with 10 serrated and two simple setae on inner margin; article-3 with nine simple and six serrated setae. Labium (Figure 5G) outer margin serrated; palp covered with numerous simple setae, terminally with three spines. Maxillule (Figure 5H) inner endite with six plumose spines distally and some setae on outer margin; outer endite with two plumose setae subdistally, 11 spines distally and numerous setae on outer margin. Palp of two articles, second article with eight setae with rows of hooks in distal part. Maxilla (Figure 6A) outer lobe of moveable endite with two plumose setae subdistally, two simple and three plumose setae distally; inner lobe of moveable endite with six simple setae; outer lobe of fixed endite with three simple and one serrated setae; inner lobe of fixed endite with row of 27 simple setae and five plumose setae. Maxilliped (Figure 6B) basis naked; palp article-1 with short seta on outer margin and elongated simple seta on inner margin; article-2 with 18 serrated and three simple setae on inner margin and one long seta on distal outer margin; article-3 with seven setae subdistally; last article with one simple seta on outer margin and five simple setae on inner margin. Endite (Figure 6C) outer margin with minute setae; inner margin with three coupling hooks and four plumose spines; distal margin with one simple, five multifurcated and six bifurcated setae; caudoinner seta simple. Epignath (Figure 6D) massive; distal seta half as long as lobe, with fine setation.

Cheliped (Figure 6E) basis 3.2 times as long as wide, with three short setae dorsally, row of short setae and spine ventrally and tuft of four setae ventrodistally, distally with tubercle; merus half as long as basis, with one dorsal seta and four setae and one spine ventrally; carpus 4.3 times as long as wide, with four (three long and one short) setae ventrally, pair of seta ventrodistally and dorsodistally; propodus 2.3 times as long as wide, with two unequal setae near dactylus insertion; fixed finger with six setae ventrally and row of fine setae on cutting edge; dactylus as long as fixed finger, with three middorsal setae.

Pereopod-1 (Figure 6F) basis 4.3 times as long as wide, with seven penicillate setae dorsally, row of paired short setae ventrally and tuft of four setae ventrodistally; ischium with one dorsal seta and three ventral setae; merus 0.4 times as long as wide, with one seta ventrally, two setae and spine ventrodistally and five setae and spine dorsodistally; carpus 1.3 times as long as merus, with six setae and one spine dorsally, two spines distally and four setae and two spines ventrally; propodus half as long as carpus, with four setae and two spines dorsally and one serrated and three simple setae and four spines ventrally; dactylus with two setae dorsally and four denticles ventrally, dactylus and unguis slightly shorter than propodus.

Pereopod-2 (Figure 7A) basis 6.3 times as long as wide, with penicillate seta on dorsal and ventral margin, ventrodistally with four simple setae; ischium with seta; merus 0.3 times as long as basis, with three setae dorsally, one seta distally and four setae ventrally; carpus half as long as basis, with five setae ventrally, five setae dorsally, two setae distally and short spine subdistally; propodus 0.8 times as long as carpus, with one spine and three setae ventrally, two setae and two spines distally; dactylus half as long as carpus, with three ventral denticles accompanied by short setae.

Pereopod-3 (Figure 7B) basis 5.7 times as long as wide, with pair of minute setae on lateral margins and two simple setae ventrodistally; ischium with one dorsal and one ventral setae; merus 0.3 times as long as basis, with three setae ventrodistally; carpus 1.5 times as long as merus, with six setae ventrally, two spines ventrodistally and four setae dorsodistally; propodus slightly longer than merus, with four setae and one spine ventrally, five setae dorsally and two spines subdistally; dactylus with two dorsal setae and two ventral denticles, dactylus and unguis 0.9 times as long as propodus.

Pereopod-4 (Figure 7C) basis 3.7 times as long as wide, with one penicillate seta dorsally, one penicillate and two minute setae ventrally and two setae ventrodistally; ischium with one dorsal and one ventral setae; merus 0.3 times as long as basis, with four setae ventrodistally and single seta dorsodistally; carpus about half as long as basis, with total of 11 setae in two rows distally; propodus 0.7 times as long as carpus, with penicillate seta dorsally and 11 simple setae distally and subdistally; dactylus with two ventral denticles; unguis broken.

Pereopod-5 (Figure 7D) basis six times as long as wide, with one simple and three penicillate setae dorsally, four setae ventrally and two setae ventrodistally; ischium with simple seta; merus 0.4 times as long as basis, with three setae dorsodistally and two setae ventrodistally; carpus 1.2 times as long as merus, with one seta ventrally, two setae ventrodistally and two setae dorsodistally; propodus about as long as merus, with penicillate seta dorsally, strong seta ventrally and distally and row of short spines ventrally and distally; dactylus with two dorsal setae and one ventral denticle, with unguis subequal merus.

Pereopod-6 (Figure 7E) similar to pereopod-5, but merus with four distal setae, carpus with six distal setae, propodus with three long dorsodistal setae and dactylus with three dorsal setae.

Pleopods absent.

Uropods broken.

REMARKS

This species was primarily classified as genus Apseudes (Kudinova-Pasternak, Reference Kudinova-Pasternak1970) but was recently moved to Fageapseudes on the basis of lack of rostrum and shape of pereonites 1 and 6 and pleon (Jóźwiak, Reference Jóźwiak2014). Fageapseudes vitjazi differs from both F. suprema and F. bicornis by having well developed lateral apophyses on pleonites, labial palp with three spines, ventral denticles on dactylus of all pereopods and cheliped basis with ventral spine. It can be distinguished from F. brachyomos Bamber, Reference Bamber2007 by well developed, acute lateral apophyses on pleonites and from F. retusifrons (Richardson, 1912) by relatively short apophyses on pereonites and pereopod-1 coxa. Taking into account the shape of pleonites (including presence of ventral bulbus), armament of cheliped and pereopods 2–6, F. vitjazi resembles F. pluma Drumm & Bamber, 2013; however, both species can be distinguished by the slenderness of their second mandibular palp, carpus and propodus of pereopod-1 (see Jóźwiak, Reference Jóźwiak2014) and by the shape of caudoinner seta of maxillipedal endite.

The main difference between descriptions of F. vitjazi from this paper and Kudinova-Pasternak (Reference Kudinova-Pasternak1970) is the number of ventral spines on pereopod-1 propodus, since this study showed four in comparison to the five spines stated in the original description.

DISTRIBUTION

Fagapseudes vitjazi was recorded east off Kurile Islands in depths between 4857 and 5408 m (Kudinova-Pasternak, Reference Kudinova-Pasternak1970, Reference Kudinova-Pasternak1973; KuramBio collection).

KEY FOR IDENTIFICATION FAGEAPSEUDES SPECIES

1. 1. Pleonites with distinct lateral apophyses2

   • – Pleonites without lateral apophyses4

2. 2. Pleonites with ventral bulbous processes3

   • – Pleonites without ventral bulbous processes F. retusifrons

3. 3. Cheliped exopod with two setae terminallyF. pluma

   • – Cheliped exopod with three setae terminally F. vitjazi

4. 4. Labial palp with three terminal spinesF. brachyomos

   • – Labial palp with one terminal spine5

5. 5. Mandibles body with crenulated outer margin, palp article-2 ten times as long as wideF. bicornis

   • – Mandibles body with smooth outer margin, palp article-2 five times as long as wideF. suprema

Genus Leviapseudes Sieg, Reference Sieg, Gruner and Holthuis1983
Leviapseudes zenkevitchi (Kudinova-Pasternak, Reference Kudinova-Pasternak1966)
(Figures 8–10)

Apseudes sp. Belyaev, Reference Belyaev1966, p. 87; Apseudes zenkevitchi Kudinova-Pasternak, Reference Kudinova-Pasternak1966, pp. 518–521; Leiopus zenkevitchi Lang, Reference Lang and Wolff1968, p. 25; Leviapseudes zenkevitchi Sieg, Reference Sieg, Gruner and Holthuis1983, p. 176.

Fig. 8.

Leviapseudes zenkevitchi (Kudinova-Pasternak, Reference Kudinova-Pasternak1966), neotype juvenile male: (A) body; (A’) pleon dorsal view; manca: (B) cheliped; (C) pereopod-1. Scale bars: A, A’, 1 mm; B–C, 0.2 mm.

Fig. 9.

Leviapseudes zenkevitchi (Kudinova-Pasternak, Reference Kudinova-Pasternak1966), manca: (A) antennule; (B) antenna; (C) right mandible; (C’) mandibular palp; (D) maxillule; (D’) maxillular palp; (E) maxilla; (F) maxilliped; (F’) articles 3 and 4 of maxillipedal palp; (G) maxillipedal endite. Scale bars: 0.2 mm.

Fig. 10.

Leviapseudes zenkevitchi (Kudinova-Pasternak, Reference Kudinova-Pasternak1966), manca: (A) pereopod-2; (B) pereopod-3; (C) pereopod-4; (C’) dactylus and unguis of pereopod-4; (D) pereopod-5; (E) pereopod-6. Scale bars: 0.2 mm.

MATERIAL EXAMINED

Neotype juvenile male (drawn in Figure 8), 12.2 mm long (So 223, Station 7–9; coordinates: 43°2.87′N–43°1.50′N 152°59.45′E–152°58.35′E, EBS; water depth: 5121–5126 m) (cat. no. ZMH K-44340) 17 August 2012.

Additional material: one manca dissected on slides (So 223, Station 6–11; coordinates: 42°29.58′N–42°28.47′N 154°0.04′E– 153°59.67′E, EBS; water depth: 5290–5305 m) (cat. no. ZMH K-44341) 15 August 2012.

DIAGNOSIS

Pleonites without lateral apophyses, antenna squama slim, with reduced setation, cheliped basis with ventral spine, cheliped carpus elongated (6.4 times as long as wide), and pereopod-1 propodus shorter than carpus.

DESCRIPTION

Juvenile male. Body (Figure 8A, A’) elongated, nine times as long as wide. Carapace 17% of total body length, with well developed rostrum and acute eyelobes that lack visual elements; well developed apophyses additionally in front of branchial chambers. Pereon of six free pereonites, length-width ratio 0.4, 0.8, 1.7, 2.9, 2.8 and 2.1 respectively; pereonites 3–6 with lateral apophyses. Pleon 31% of total body length, of five free pleonites, pleonites trapezoidal without lateral apophyses, subequal in size; pleotelson longer than last three pleonites.

Antennule (Figure 9A) peduncle article-1 6.6 times as long as wide, with two penicillate setae on inner margin and one simple and six penicillate setae on outer margin; article-2 0.3 times as long as article-1, with one simple and six penicillate setae subdistally; article-3 0.6 times as long as article-2, with four minute setae distally; article-4 naked. Outer flagellum with 11 segments, segment-9 with two setae and aesthetasc; last segment with one penicillate and four simple setae. Inner flagellum of three segments; segment-1 with one minute seta, segment-2 with one penicillate seta and segment-3 with one penicillate and three simple setae distally.

Antenna (Figure 9B) peduncle article-1with distaloinner projection; article-2 2.4 times as long as article-3, naked; squama elongated, with two unequal simple setae distally; article-3 with one simple inner seta; article-4 2.6 times as long as article-3, with two penicillate setae distally; article-5 1.4 times as long as article-4, with four penicillate setae distally and subdistally. Flagellum of three segments; segment-1 with simple seta reaching end of antenna; segment-2 with two simple setae; last segment with four distal setae.

Mouthparts. Right mandible (Figure 9C) incisor with five distal denticles; setiferous lobe with five bi- or trifurcated setae; palp (Figure 9C’) of three articles; article-1 with single inner seta; article-2 4.2 times as long as wide, with three serrated setae in distal inner part; article-3 with distal inner row of nine serrated setae increasing in length towards the end of article. Maxillule (Figure 9D) inner endite with simple setae on inner and outer margins, distally with one serrated and two simple spines; outer endite with three setae ventrally, three subdistally and nine distal spines; palp (Figure 9D’) of two articles, article-2 with two simple setae and five setae terminated with row of small hooks. Maxilla (Figure 9E) outer lobe of moveable endite with two plumose setae subdistally and five plumose setae distally; inner lobe of moveable endite with seven plumose setae; outer lobe of fixed endite with one simple, two plumose, four multifurcated and three bifurcated setae; inner lobe of fixed endite with row of 25 setae and three thick plumose setae. Maxilliped (Figure 9F, F’) basis naked; palp article-1 with one short outer seta and one inner seta reaching end of last article; article-2 with two long simple outerodistal setae and five simple and nine serrated setae on inner margin; article-3 with four simple setae on inner margin; last article with five simple setae. Endite (Figure 9G) on inner margin only one coupling hook left; subdistally with three bi- and five multifurcate setae; distally with one simple seta, two bifurcate setae with pointed tip and four multifurcate setae (one seta broken); caudoinner seta leaf shaped.

Cheliped (Figure 8B) basis slim, 4.2 times as long as wide, ventrally with three minute setae in proximal part, one spine at midlength and one long seta in distal part; exopod of three articles, last article with four setae distally; merus half as long as basis, with three ventral setae; carpus 6.4 times as long as wide, with two rows of four setae: ventral and dorsal; propodus 1.5 times as long as wide, with one short and three long setae dorsally and single seta ventrally near dactylus insertion; fixed finger with two ventral setae, cutting edge with few simple setae and denticles; dactylus slightly longer than fixed finger, with three middorsal setae.

Pereopod-1 (Figure 8C) basis 4.3 times as long as wide, with two minute and two penicillate setae dorsally and two minute setae ventrally; ischium with simple seta; merus four times as long as wide, with one spine and three setae ventrally, two simple setae distally and two dorsodistally; carpus half as long as merus, with four setae and one spine dorsally and three setae and two spines ventrally; propodus 0.7 times as long as carpus, with three setae and two spines dorsally and one seta and six spines ventrally; dactylus with dorsal seta and three ventral denticles, dactylus and unguis as long as carpus.

Pereopod-2 (Figure 10A) basis 8.5 times as long as wide, with two penicillate setae dorsally, two minute ventrally and one seta ventrodistally; ischium with single seta; merus about 0.4 times as long as basis, with three setae ventrally and one seta dorsally; carpus half as long as basis, with four setae dorsally, one short seta distally and five setae ventrally; propodus 0.8 times as long as carpus, with five setae dorsally, two spines distally and six setae and two spines ventrally; dactylus with one dorsal seta and one seta ventrally at unguis insertion, dactylus and unguis as long as carpus.

Pereopod-3 (Figure 10B) basis 8.8 times as long as wide, with two penicillate setae ventrally and one simple seta ventrodistally; ischium with single seta; merus 0.3 times as long as basis, with short seta dorsodistally and one long seta ventrodistally; carpus 1.5 times as long as merus, with three setae ventrally, one distally and two dorsodistally; propodus 0.8 times as long as carpus, with four setae dorsally, six setae ventrally and two distal spines; dactylus as long as merus, with one dorsal and one ventral setae, dactylus and unguis half as long as basis.

Pereopod-4 (Figure 10C, C’) basis 9.6 times as long as wide, with two penicillate setae dorsally and simple seta ventrodistally; ischium with one seta; merus with one seta dorsodistally and two setae ventrodistally; carpus 1.8 times as long as merus, with one seta at midlength ventrally and eight setae distally; propodus 0.8 times as long as carpus, with one penicillate seta dorsally and 14 setae dorsodistally; dactylus short, with dorsal seta and ventrodistal apophysis, unguis trifurcated (Figure 10C’).

Pereopod-5 (Figure 10D) basis almost nine times as long as wide, with three penicillate setae dorsally, one penicillate seta ventrally and one simple seta ventrodistally; ischium with single seta; merus with one ventral seta; carpus twice as long as merus, with five setae in distal part; propodus as long as carpus, with one penicillate seta dorsally, three simple setae dorsodistally, two strong setae ventrally and ventral row of short spines; dactylus as long as propodus, with three dorsal and two ventral setae, together with unguis longer than half of basis.

Pereopod-6 (Figure 10E) rudimental and without setation.

REMARKS

The main characters differentiating L. zenkevitchi from remaining species of the genus are:

• • lack of lateral apophyses on pleonites. Apophyses are present in L. abberans (Lang, Reference Lang and Wolff1968), L. bipartitus Larsen, Reference Larsen2005, L. demerarae Băcescu, 1984, L. galatheae (Wolff, 1956), L. gracillimus (Hansen, Reference Hansen1913), L. hanseni (Lang, Reference Lang and Wolff1968), L. longispina Băcescu, 1983, L. macaronesia Larsen, 2012, L. pleonudus Błażewicz-Paszkowycz & Larsen, 2004, L. preamazonica Băcescu, 1984, L. tenuimanus Błażewicz-Paszkowycz & Larsen, 2004 and L. wolffi (Lang, Reference Lang and Wolff1968).

• • ventral spine on cheliped basis. In L. conspicuus (Lang, Reference Lang and Wolff1968), L. demerarae, L. drachi Băcescu, 1984, L. gracilis (Norman & Stebbing, 1886), L. gracillimus, L. segonzaci gasconicus Băcescu, 1984, L. segonzaci segonzaci Băcescu, 1981, cheliped is smooth.

• • pereopod-4 dactylus-unguis comb-like. Smooth dactylus-unguis is present in L. aberrans, L. angelikae Jóźwiak & Błażewicz-Paszkowycz, Reference Jóźwiak and Błażewicz-Paszkowycz2007, L. gracillimus, L. leptodactylus (Beddard, 1886), L. macaronesia, L. preamazonica, L. shiinoi (Lang, Reference Lang and Wolff1968), L. tenuimanus.

• • pereopod-1 basis ventrodistally only with simple setae. In L. angelikae, L. bipartitus, L. conspicuus, L. macaronesia and L. pleonudus ventrodistal corner of pereopod-1 basis has a simple spine, while in L. gracilis, L. leptodactylus, L. longispina, L. shiinoi and L. wolffi it is terminated with well developed acute process.

Moreover L. zenkevitchi differs from L. caecus (Willemoes-Suhm, 1875) by having reduced, slim squama with only two setae (in latter species at least nine setae). From L. weberi (Nierstrasz, 1913) it differs by elongated carpus of cheliped (6.4 times as long as wide in L. zenkevitchi and 3.2 times as long as wide in L. weberi). Leviapseudes zenkevitchi can be distinguished from L. zenkevitchioides by having propodus of pereopod-1 shorter than carpus (in latter species it is distinctly longer).

The specimens of L. zenkevitchi described herein differ slightly from the original description of this species (Kudinova-Pasternak, Reference Kudinova-Pasternak1966), as its pereonites from 4 to 6 and cheliped dactylus are narrower. This variability can be explained by the fact that the type specimen was a mature female and our redescription is based on mancas.

DISTRIBUTION

Leviapseudes zenkevitchi is a widely distributed species including Kurile Islands, Kermadec, the Caribbean Sea and Grenada, with the original type locality in the North-east Pacific – 40°19.7′N 175°45.3′E, in depths from 1067 to 6065 m (Kudinova-Pasternak, Reference Kudinova-Pasternak1966; Kudinova-Pasternak & Pasternak Reference Kudinova-Pasternak and Pasternak1978; KuramBio collection).