Leviapseudes angelikae, Jóżwiak, Piotr & Błażewicz-Paszkowycz, Magdalena, 2007

Jóżwiak, Piotr & Błażewicz-Paszkowycz, Magdalena, 2007, Apseudomorpha (Malacostraca: Tanaidacea) of the ANDEEP III Antarctic Expedition, Zootaxa 1610, pp. 1-25 : 16-24

Leviapseudes angelikae n. sp.

( Figs 8–12 )

Material examined: Holotype – preadult female, ( K41401 ), ANTXXII/3 sta. PS67/016–10, 41º7,06'– 41º6.99'S, 9º54.88'– 9º54.88'E, 14 Feb 2005, depth 4669–4687 m. Paratypes – two females, two males, two mancas ( K41402 ), ANTXXII/3, sta. PS67/016–10, 41º7.06'– 41º6.99'S, 9º54.88'– 9º54,88'E, 14 Feb 2005, depth 4669–4687 m; one female, ( K 41399 ), ANTXXII/3 sta. PS67/102–6, 65º34.36'S, 36º31.08'W, 0 5 Mar 2005, depth 4802 m; one female, one manca ( K41403 ), ANTXXII/3, sta. PS67/059–5, 67º29.74'– 67º29.61'S, 0º1.93'– 0º2.19'W, 14 Feb 2005, depth 326.4– 309.3 m.

Type locality: At 41º7,06'– 41º6,99'S, 9º54,88'– 9º54,88'E, depth 4687– 4669 m.

Etymology: The species named in honor of Prof. Angelika Brandt (Zoological Museum and University of Hamburg) who collected the material and made it available for the study.

Diagnosis: Preadult female. Carapace with one spine in front of respiratory chamber. Ocular lobe spiniform. Pereonites from 2 to 6 and pleonites with well developed lateral spiniform apophyses and hyposphenia. Cheliped basis with small spine on ventral margin. Pereopod-1 basis with distoventral spiniform seta. Pereopods 4–6 carpus longer than merus or propodus, with three spiniform setae distoventrally. Pereopods 5 and 6 propodus with three spiniform setae ventrally. Pereopods 5 and 6 dactylus/unguis 1.5 longer than propodus. Pleopods reduced in size in female with rudimentary oostegities, but well developed in adult female and all stages of male.

Description: of the female with rudimentary oostegites ( Figs 8 A, B). Body 11 mm long, 9.5 times as long as wide; carapace about 15% of total body length, with one lateral spiniform apophyses in front of respiratory chamber; ocular lobes well developed, spiniform, without pigmentation; pereonites 2 to 6 longer than wide, each with anterolateral apophysis; pereonite-2 1.5 times as long as pereonite-1; pereonite-3 1.3 times as long as pereonite 2; pereonite-4 subequal pereonite-5, 1.25 times as long as pereonite-3; pereonite-6 little shorter than pereonite-5; pereonites and pleonites with hyposphaenium; pleon long, about 30% of total body length, pleonites each of equal length, with posterolateral apophysis; pleotelson narrow, as long as last three pleonites.

Antennule ( Fig. 9 A) peduncle article-1 3.5 times as long as article-2, with short setae in groups on outer margin and with one simple seta on inner margin; article-2 with two minute setae dorsally and four setae distally; article-3 half as long as article-2, with one simple seta distally. Article-4 naked. Inner flagellum broken. inner flagellum more than twice as long as peduncle, of 22 articles; some articles with pair of short simple setae Distally, article-21 with two simple setae and one aesthetasc; distal article with four simple setae.

Antenna ( Fig. 9 B) article-1 wider proximally, about twice as wide as article-2, naked; article-2 1.7 times as long as article-1, with one short simple seta on each lateral margin; squama as long as peduncle article-2, with six setae (five short and one long); article-3 shortest, with one subdistoinner simple seta; article-4 3.6 as long as article-3, with one simple and one pinnate seta subdistally; article-5 as long as article-4, with three simple and three pinnate setae. Flagellum consists of five articles; article-1 0.4 times as long as distal article of peduncle, with one simple seta distally (exceeding following article); article-2 little longer than article-1, with three simple setae distally (two medium and one minute); article-4 with two simple and one pinnate setae distally; article-5 with three simple setae terminally.

Mouthpart. Labrum not recovered. Mandible ( Fig. 9 C) molar process ( Fig. 9 C”) wider and longer than incisor, with numerous minute setae distally. Palp 3-articled; article-1 half as long as article-2, with one short and one long seta distally; article-2 1.4 as long as article-3, with row of simple setae at middle; article-3 with row of simple setae increasing in length distally. Left mandible incisor ( Fig. 9 C) with about five blunt denticles; lacinia mobilis slender, similar in size to incisor; setal row of six multifurcated setae. Maxillule ( Fig. 9 D) palp 2-articled, tipped by five setae. Outer endite tipped by ten spiniform setae and with two simple subdistal setae. Inner margin with microtrichiae. Inner endite with three plumose and two simple setae distally; microtrichiae on both margins. Maxilla ( Fig. 9 E) outer lobe of movable endite with microtrichiae on outer margin and with two long simple setae; five simple setae distally. Inner lobe of movable endite with seven simple and one plumose setae. Outer lobe of fixed (inner) endite with two simple and four multifurcate setae. Inner lobe of fixed endite with row of four plumose setae distally and row of numerous simple setae subdistally; inner margin with minute spines. Labium ( Fig. 9 F) lobe with microtrichiae on ventral margin; palp with numerous simple setae on both margins, and with three distal robust setae. Maxilliped ( Figs 9 H, I) endite with row of bifurcate setae on distal margin; in subdistal part leaf-shaped seta; inner margin with row of eight simple setae diminished in size proximally. Palp article-1 with one short seta distally on outer margin and two long, simple and two plumose setae on inner margin; article-2 with two plumose and eight simple setae on inner margin and three short simple setae outerdistally; article-3 with five long simple setae; article-4 with five simple setae terminally.

Epignath ( Fig. 9 G) basal plate naked; terminal seta setulated distally shorter than basal plate.

Cheliped ( Fig. 10 A) basis shorter than carpus, with small ventral spine and five simple setae distoventrally; merus almost half as long as carpus, with four simple setae ventrally and two simple setae distodorsally; carpus with numerous long setae on ventral margin and two short setae on dorsal margin; propodus with three long and one short setae near dactylus insertion and with two setae dorsally. Fixed finger 1.4 times longer than propodus, with three long and one short setae ventrally; inner margin with row of well calcified teeth and row of short setae. Dactylus narrow, longer than fixed finger. Exopod present (not drawn).

Pereopod-1 ( Fig. 10 B) basis twice as long as merus, four times as long as wide, with one pinnate seta dorsally, minute setae ventrally, and one spiniform seta distoventrally; merus about twice as long as carpus, with six simple setae (distal seta robust) ventrally, and group of simple setae along article; carpus with row of simple and spiniform setae ventrally and with one spiniform seta and three simple setae dorsodistally; propodus 1.4 times as long as carpus, with row of eight spiniform setae ventrally and five strong setae dorsally; dactylus 0.6 times as long as propodus, with short seta dorsally; unguis broken. Exopod of two articles, distal article with five plumose setae.

Pereopod-2 ( Fig. 10 C) basis about as long as combined length of ischium, merus and carpus, with one pinnate seta dorsally and minute setae ventrally; ischium with short seta; merus 0.4 times as long as basis, with five (two long and three short) setae ventrally and one seta dorsodistally; carpus subequal in length to merus, with simple setae ventrally and distally, one spiniform seta distoventrally; propodus as long as carpus, with row of simple setae on both margins and five spiniform setae distally; dactylus 0.6 times as long as propodus, with minute seta dorsally; unguis broken.

Pereopod-3 ( Fig. 10 D) basis as long as combined length of ischium, merus and carpus, 3.8 times as long as wide, with one minute seta ventrally and distally; ischium with simple seta; merus 0.4 times as long as basis, with three minute setae; carpus 1.3 times as long as merus, with two setae on ventral margin and one simple and three spiniform setae distally; propodus 0.8 times as long as carpus, with three simple setae ventrally, one simple seta dorsally and six short spiniform setae at dactylus insertion; dactylus half as long as propodus; unguis about 0.8 as long as dactylus; dactylus and unguis as long as merus.

Pereopod-4 ( Fig. 10 E) basis as long as merus, carpus and half of propodus combined, with one pinnate and two minute setae ventrally and one minute seta distally; ischium with simple seta; merus about as long as half of carpus, with two minute, ventral setae; carpus with one simple seta ventrally, four simple and two spiniform setae distally; propodus 0.6 as long as carpus, with one pinnate seta dorsally, one minute seta ventrally and eight simple setae distally; dactylus twice longer than unguis, dactylus and unguis as long as merus.

Pereopod-5 ( Fig. 10 F) basis as long as combined length of merus, carpus and half of propodus, 5.5 times as long as wide, with two minute setae ventrally and two short and two pinnate setae dorsally; ischium with simple seta; merus about 0.3 times as long as basis, with two minute setae distally; carpus 1.5 times as long as merus, with one short seta ventrally, three spiniform setae ventrodistally and three minute setae dorsodistally; propodus 0.8 times as long as carpus, with one minute and one pinnate setae dorsally, three spiniform setae and row of numerous short, spiniform setae ventrally, and two spiniform setae distally; dactylus little shorter than propodus; unguis 0.75 times as long as dactylus; combined 1.5 times as long as propodus.

Pereopod-6 ( Fig. 10 G) as pereopod-5, but carpus with only one simple and two spiniform setae distally; dactylus with two simple setae on dorsal margin.

Pleopods ( Fig. 10 H) in five pairs; basal article five times as long as wide, naked; exopod 0.7 times as long as endopod, with two simple setae terminally; endopod with two simple setae terminally.

Uropod ( Fig. 10 I) basis with four minute setae, five times as long as wide. Exopod 7-articled; article-3 with pair of simple setae subdistally; article-7 with two long setae terminally. Endopod missing.

Females with well developed oostegites have fully developed pleopods.

Description of adult male: Similar to female, but pleon more massive. Carapace about 13% of total body length, tapering proximally, with one median spine in both sides, rostrum pointed; ocular lobe great, spiniform, without visual elements. Pereonites 2-6 with well developed lateral spines proximally. Pereonites and pleonites with hypospheniae. Pereonite-1 wider than long; pereonite-2 1.6 times longer than pereonite-1; pereonite-3 twice longer than pereonite-1; pereonite-4 subequal in length to pereonite-5; pereonite-6 as long as pereonite-3. Pleon about 30% of total body length; pleonites equal in length; pleotelson as long as last three pleonites.

Antennule ( Fig. 11 B) peduncle article-1 four times as long as article-2, with two pinnate setae on inner margin and some simple setae on both margins; article-2 with one pinnate seta on distal margin and two minute setae on outer margin; article-3 0.6 as long as article-2, with two minute setae distally. Inner flagellum of seven articles, some articles with two minute setae distally; last article with three setae terminally. Outer flagellum of twenty three articles; most of articles with numerous long setae distally.

Antenna ( Fig. 11 C) article-1 with ventral process; article-2 little shorter than squama, with two minute setae; article-3 short, with one minute seta; article-4 three times longer than article-3, with two setae on inner margin; article-5 longest, with five simple setae. Squama little longer than peduncle article-2, with ten setae. Inner flagellum of five articles; article-1 0.4 as long as article-5 peduncle, with one short and three long setae; articles 2 and 4 with two simple setae distally; last article tipped by four simple setae.

Cheliped ( Fig. 12 A) coxa with small spine; basis narrow, about 3.5 times longer than wide, a little shorter than carpus, with short spine ventrally, four setae distoventrally and couple minute setae on both margins; merus with one seta distodorsally and seven setae ventrally; carpus with four setae ventrally, two at middle and three distally; propodus with two setae dorsally and three distodorsally near dactylus insertion; fixed finger with five setae ventrally and row of short spines and setae on inner margin; dactylus with two setae; dactylus and unguis combined longer than fixed finger.

Pereopod-1 ( Fig. 12 B) similar to female pereopod-1.

Pereopod-2 ( Fig. 12 C) basis as long as combined length of merus and carpus, with one pinnate seta dorsally and couple minute setae ventrally; ischium with simple seta; merus 0.4 as long as basis with three setae ventrally, two distoventrally and one distodorsally; carpus 1.3 longer than merus, with nine setae ventrally (some of them short, spiniform), two distoventrally, two distodorsally and two dorsally; propodus as long as carpus, with spines and setae along article; dactylus broken.

Pereopods 3–6 ( Fig. 12 D–G) similar to female pereopod 3–6, respectively.

Pleopods ( Fig. 12 H) biramous, well developed, in five pairs; basal article longer than each ramus, with plumose seta distally. Exopod of two articles; article-1 half as long as article-2, with one long, plumose seta distally; article-2 with about nineteen long, plumose setae. Endopod 1-articled, with about eighteen plumose setae.

Uropod ( Fig. 12 I) basal article over three times longer than wide, with short spiniform setae distally. Endopod broken. Exopod consist of nine articles, some with two setae distally.

Distribution: South-west of South Africa, north of the Weddell Sea and north of Martha Coast at the depth range from 309.3 to 4802 m.

Remarks: Leviapseudes angelikae n. sp. has the fourth pereopod dactylus normally developed in contrast to numerous members of Leviapseudes (see BłaŻewicz-Paszkowycz and Larsen, 2004) in which is modified to a hook. The Leviapseudes with a normal dactylus/unguis on pereopod-4 are seven species: L. aberrans ( Lang, 1968) , L. caecus ( Willemoes-Suhm, 1875) , L. gracillimus ( Hansen, 1913) , L. leptodactylus ( Beddard, 1886) , L. preamazonica Bacescu, 1984 , L. shiinoi ( Lang, 1968) , and L. weberi ( Nierstrasz, 1913) .

Leviapseudes angelikae has a slender body emphasized by elongated (2.5–3 times as long as wide) pereonites from 4 to 6. This feature allows separation of the new species from the seven mentioned above. Additional characters regard mostly the cheliped, pereopod-1 and pereopods from 4 to 6. Slender chelae with a cheliped carpus six times as long as wide distinguish the new species from L. weberi , which has a compact chela and cheliped carpus barely three times as long as wide. Leviapseudes abberans has the pereopod-1 carpus clearly longer than the propodus, while L. gracillimus has the propodus of pereopod-4 subequal to the carpus. In contrast, the new species has a carpus of pereopod-1 as long as the propodus, while the carpus of pereopods 4 to 6 is (beside basis) the second longest article.

L. leptodactylus has over eight strong distal setae on the carpus of pereopod-4. This separates the species from L. angelikae , which has no more than three long and two short setae there. A similar scarce setation is observed in the male of L. shiinoi , but the four-articled accessory flagellum of the antennule and the relatively strong ventro-distal spine on the pereopod-1 basis and cheliped ventrally distinguish it from L. angelikae . Leviapseudes caecus is a poorly described species. The few drawings presented by the author (Willemoes- Suhm, 1875) show nine articles on the antenna flagellum, in contrast to the six-articulated antennae flagellum of L. angelikae the adult female.

Preadult females (with rudimental oostegites) of L. angelikae have vestigial pleopods which are fully developed in adult female (with developed oostegites). A similar situation was observed by Lang (1968) in Leviapseudes wolffi ( Lang, 1968) , and attributed to ontogenethic variation.

Figures

FIGURE 8. Leviapseudes angelikae n. sp. Holotype female. A, Body dorsal view; B, Body lateral view. Scale line = 1 mm.

FIGURE 9. Leviapseudes angelikae n. sp. Paratype female. A, Antennule; B, Antenna; C, Left mandible; C', Incisor, lacinia mobilis and setiferous lobe; C' ', Molar process (distal end); D, Maxillule; E, Maxilla; F, Labium; G, Epignath; H, Maxilliped; I, Maxillipedal endite. Scale line = 1 mm for A, B; 0.1 mm C-I.

FIGURE 10. Leviapseudes angelikae, n. sp. Paratype female. A, Cheliped; B, Pereopod- 1; C, Pereopod- 2; D, Pereopod- 3; E, Pereopod- 4; F, Pereopod- 5; G, Pereopod- 6; H, Pleopod; I, Uropod. Scale line = 1 mm.

FIGURE 11. Leviapseudes angelikae n. sp. Male. A, Body Lateral view; B, Antennule; C, Antenna. Scale line = 1 mm.

FIGURE 12. Leviapseudes angelikae. Male. A, Cheliped; B, Pereopod- 1; C, Pereopod- 2; D, Pereopod- 3; E, Pereopod- 4; F, Pereopod- 5; G, Pereopod- 6; H, Pleopod; I, Uropod. Scale line = 1 mm.