Leviapseudes Sieg, 1983

Larsen, Kim, 2012, Tanaidacea (Crustacea) from Macaronesia II. The deep-water fauna from the Azores archipelago, Portugal, Zootaxa 3250, pp. 26-42 : 27-32

publication ID	https://doi.org/ 10.5281/zenodo.280575
DOI	https://doi.org/10.5281/zenodo.6178261
persistent identifier	https://treatment.plazi.org/id/03D387C1-FFB1-2563-86B7-FE6CFCC6E525
treatment provided by	Plazi
scientific name	Leviapseudes Sieg, 1983
status

Treatment

Genus Leviapseudes Sieg, 1983 View in CoL

Diagnosis (Modified after Błażewicz-Paszkowycz & Larsen 2004). Female. Pereonite 6 rectangular. Pleonites often much narrower than pereonite 6, sometimes as long as wide. Cheliped carpus as long as or longer than fixed finger. Pereopod 1 merus longer than carpus. Pereopod 4 dactylus/unguis sometimes reduced to a claw. Pleopods, if present, with bi-articulate exopod.

Male. Pereonite 6 with clearly identifiable genital cone. Antennule after terminal molt with numerous aesthetascs. Pereopod 4 dactylus/unguis, if reduced to a claw, less so than in female. Pleonites always with lateral epimera, and epimera larger than in female.

Type species. Leiopus longidactylus Beddard, 1886

Gender of generic name. Masculine.

Remarks. For generic remarks see Larsen (2005). Recent changes by Guțu (2006) have removed a large number of species from this genus. At present, it contains 26 species/subspecies ( Anderson 2011) including the one described here.

Leviapseudes macaronesia n. sp. ( Figs 1–2 View FIGURE 1 View FIGURE 2 )

Material examined. Holotype, non-ovigerous Ƥ. Body length 11.5 mm MMF 42244. Station L09D27(S1), 38º35'319"N. 28º05'129". South of S. Jorge Island, 1114 m depth,

Diagnosis. Female. Carapace with spiniform process in front of the respiratory chamber. Pereonites 2–6 with spiniform lateral process. Pleonites longer than wide and with pointy lateral epimera. Cheliped basis with ventral spiniform seta; carpus longer than basis; dactylus longer than fixed finger. Pereopod 1 basis without proximal spines, with ventro-distal spiniform seta; merus 0.8 times as long as basis and twice as long as carpus; carpus and propodus of similar length; dactylus unguis with weak ventral serration (only two small spines). Pereopods 2–6 unguis with apical curled-leaf-shaped setae. Pereopod 4 dactylus/unguis not reduced to a claw.

Male unknown.

Etymology. Named after the Macaronesian region where this EMEPC expedition was conducted.

Description. Female.

Body ( Fig. 1 View FIGURE 1 A) elongate, almost 15 times as long as wide. Carapace, including rostrum, longer than pereonites 1 and 2 combined. Ocular spines well developed, without visual elements. Lateral spines prominent. Rostrum reaching one-third of first antennular article, ventrally curved. Carapace divided into distinct lobes, the posterior one, carrying the cheliped attachment, prominent, about 0.3 times total carapace length (including rostrum). Pereon, pereonites 2–6 with anterior lateral spine. Pereonite 1 wider than long, pereonite 2 almost square, pereonites 3–6 longer than wide. All pereonites with ventral hyposphenians. Pleon less than 0.3 times as long as total body. All pleonites wider than long, with pointy epimera and bearing pleopods. Pleotelson as long as the last three pleonites combined.

Antennule ( Fig. 1 View FIGURE 1 B) 1.5 times as long as carapace. Peduncle article 1 more than twice as long as rest of peduncle (including common article), with multiple small setulose and different length simple setae. Article 2 twice as long as article 3, with four setulated- and one simple distal setae. Article 3 as long as outer flagellum article 1, with three simple distal setae. Common article with two setulated setae. Outer flagellum over three times as long as inner flagellum, consisting of 20 articles, the first nine naked, articles 11, 13, and 16 with aesthetascs; distal article with indentation at apex ( Fig. 1 View FIGURE 1 B1). Inner flagellum as long as peduncle articles 2 to 4 (common article), consists of five articles, only the three last with distal setae.

Antenna ( Fig. 1 View FIGURE 1 C) shorter than antennule peduncle. Article 1, naked with pronounced, smooth, inner process (wider than length of article 4). Article 2 as long as article 4, with one medial seta and small process at squama insertion. Article 3 as long as wide, with one distal seta. Article 4 long than article 1, with one setulose distal seta. Article 5 longer than article 4, with multiple short setulose distal and subdistal setae. Articles 6–8 each with simple or setulated distal setae. Squama arising from distal part of article 2, reaching past midlenght of article 4, with five distal or subdistal simple setae.

Mouthparts. Labrum ( Fig. 1 View FIGURE 1 D) naked with small medial process. Mandibles ( Fig. 1 View FIGURE 1 E–F) Mandibular molar process wider and longer than incisor, with numerous minute, distal denticles. Mandibular palp with three articles; article 1 with one distal seta almost as long as palp article 2; article 2 as long as molar, with distal row of pinnate, stout setae; article 3 wider than other palp articles, with distal and subdistal setae of which only the terminal one is pinnate. Left mandible ( Fig. 1 View FIGURE 1 E) incisor pointed, with eight denticles; lacinia mobilis thinner than incisor, with six denticles on distal margin; setal row consisting of four multifurcate setae arising from a common peduncle. Right mandible ( Fig. 1 View FIGURE 1 F) incisor with six denticles; setal row consisting of five bi- or multifurcate setae arising from a common peduncle. Labium ( Fig. 1 View FIGURE 1 G) lobes with multiple long setules on the outer and inner corner. Palp with numerous long setules on both margins; tipped by three bifurcate setae. Maxillule ( Fig. 1 View FIGURE 1 H) outer endite tipped by nine spiniform setae and two simple subdistal setae, row of setules on both margins; inner endite tipped with two setulose and three simple robust setae and row of setules on both margins; palp with two articles, distal articles tipped by five setae with apical serration, serration direction inwards on one side while outwards on the other. Maxilla ( Fig. 1 View FIGURE 1 I) outer lobe of movable endite with eight inner- and two outer- medially bipinnate setae; inner lobe of movable endite with two simple and four serrated setae; outer lobe of fixed endite with five simple spiniform, one simple, and two multifurcate spiniform setae; inner lobe of fixed endite with two robust setae and row of numerous distally widening setae arising from a peduncle; outer margin of maxilla body with setules and spines, ventral inner margin of maxilla body with spiniform scales. Maxilliped ( Fig. 1 View FIGURE 1 J) basis outer margin weakly setulose, inner distal corner with seta as long as basis; endite ( Fig. 1 View FIGURE 1 K) with row of one simple spiniform, nine complex spiniform setae and multiple setules and scales on ventral distal margin, subdistal part with one leaf-shaped seta; inner margin with row of ten setulated setae and two coupling hooks. Palp article 1 with one short seta on outer margin and one seta as long as basis on inner margin; article 2 with one seta as long as basis on outer margin and multiple setae on inner margin (only the proximal setae are pinnate); article 3 with five setae on inner margin; article 4 tipped by six long setae. Epignath ( Fig. 1 View FIGURE 1 L) basal part covered with setules, otherwise naked; terminal seta shorter than basal part, with few scattered setules.

Cheliped ( Fig. 2 View FIGURE 2 A) basis shorter than carpus, with small ventro-subdistal spiniform seta and row of setulated ventral setae. Merus less than half as long as carpus, with two shorter dorsodistal and four longer ventrodistal simple setae. Carpus with numerous long setae on medial and ventral margin and one shorter seta midlenght and one distal as well as two longer dorsodistal setae. Propodus as long as basis, with one small dorsodistal setae and three inner setae at dactylus insertion. Fixed finger with three longer ventral setae, tuft of simple inner distal setae, apparently without any inner denticles or small spiniform setae. Dactylus 1.2 times as long as fixed finger, with three simple dorsal setae at midlenght; ventrally smooth and naked. Exopod consisting of three articles, attached to basis right below coxa, distal article thinner than proximal article and with four plumose setae.

Pereopod 1 ( Fig. 2 View FIGURE 2 B) coxa spine well developed and as long as the coxa is wide, with two subdistal setae. Basis almost five times as long as wide and only slightly longer than merus, with few tiny simple setae scattered on both margins, and a tiny and a spiniform ventrodistal setae. Ischium with one ventral seta. Merus almost as long as basis, more than twice as long as carpus, with several dorsomedial and distal simple setae and one ventral spiniform seta. Carpus shorter than twice the width, with two ventral and one dorsodistal spiniform setae and several scattered simple setae, mostly on the dorsal margin. Propodus as long as carpus, with row of eight spiniform ventral setae, two dorsodistal spiniform setae, and distal simple setae. Dactylus and unguis combined as long as propodus, with two spines and a weak ventral projection at ventral unguis insertion. Unguis 0.25 times as long as dactylus. Exopod consisting of three articles, attached to basis right below coxa, distal article wider than proximal article and with four plumose setae.

Pereopod 2 ( Fig. 2 View FIGURE 2 C) coxa with one seta. Basis as long as the three succeeding articles combined, with two tiny simple setae on each margin. Ischium with one simple seta. Merus slightly longer than carpus, with two ventromedial and three ventrodistal simple setae. Carpus longer than propodus, with several simple setae on both margins. Propodus longer than merus, with several simple setae on both margins and row of seven smaller spiniform setae. Dactylus and unguis combined longer than carpus. Dactylus with one dorsoproximal and two distal setae. Unguis with terminal leaf-shaped seta ( Fig. 2 View FIGURE 2 C1).

Pereopod 3 ( Fig. 2 View FIGURE 2 D) as pereopod 2 except: basis with two setulose and four simple setae. Merus with only four setae. Carpus with ventrodistal spiniform seta.

Pereopod 4 ( Fig. 2 View FIGURE 2 E) as pereopod 3 except: carpus as long as merus, with one simple and three spiniform distal setae. Propodus with setulose dorsomedial seta and short serrated distal spiniform seta, longer than carpus. Dactylus/unguis not reduced to a claw ( Fig. 2 View FIGURE 2 E1).

Pereopod 5 ( Fig. 2 View FIGURE 2 F) as pereopod 2 except: merus half as long as carpus. Carpus with three spiniform distal setae. Propodus with row of short spiniform distal setae and one larger ventrodistal and two larger dorsodistal spiniform setae, dorsal margin with one setulose medial seta. Dactylus with two dorsomedial and two distal setae.

Pereopod 6 ( Fig. 2 View FIGURE 2 G) as pereopod 2 except: carpus with ventrodistal spiniform seta. Propodus with row of short spiniform distal setae and one larger distal spiniform setae on each margin, dorsal margin with one setulose medial seta.

Pleopods ( Fig. 2 View FIGURE 2 H) all in a very bad condition. Individual pleopods shorter than pleotelson. Basal article longer than endites, naked. Exopod longer than endopod, with two articles, proximal article naked, distal article with unknown number of plumose setae. Endopod with unknown number of plumose setae.

Uropod ( Fig. 2 View FIGURE 2 I) broken. Basal article three times as long as wide, with two subdistal setae arising from a peduncle. Endo- and exopod broken. Exopod article 1 with one medial seta.

Remarks. The new species is unique in having a terminal ‘curled leaf-shaped’ seta on the pereopods 2 to 6. Only one other species, L. wolffi ( Lang, 1968) , is recorded with terminal unguis setae on pereopods 2 to 6. However, in that species, the pereopod 4 dactylus/unguis is reduced to a claw and the unguis setae are not really leafshaped but appear simple ( Lang 1968:115,fig. 64c.1), although they are described as “ claw…. bifid at the tip” ( Lang 1968:116).

Four other members of the genus are recorded from the east Atlantic: L. leptodactylus ; L. segonzaci segonzaci Bäcescu, 1981 ; L. zenkevitchioides Bäcescu, 1981 ; L. caecus ( Willemoes-Suhm, 1875) . Leviapseudes segonzaci segonzaci and L. zenkevitchioides can both be separated from the new species by the pereopod 4 dactylus/unguis being reduced to a claw and L. segonzaci segonzaci additionally by having many setae on the basal article of the uropod. Leviapseudes leptodactylus was originally described by Beddard (1886) from the ‘North Atlantic’ and then supplementary redescribed by Lang (1968), also from the “North Atlantic, Siboga st. 78” ( Lang 1968:193). However, something must be wrong here, as the Siboga station 78 was taken off the coast off Borneo. Unfortunately both these descriptions are incomplete and diverge on a number of characters, making comparison difficult. Leviapseudes macaronesia can be separated from L. leptodactylus sensu Lang, 1968 by being: 1) the presence of pereopods dactyli leaf-shaped setae; 2) being twice as long relative to width as L. leptodactylus ; 3) having a pereopod 1 carpus and propodus of similar length. Differences from L. leptodactylus sensu Beddard, 1886 include pereopod 1 missing proximal spines, having a carpus and propodus of similar length and serration on the dactylus. Also the pereopods dactyli leaf-shaped setae seem to be missing in Beddard’s (1886) description. Leviapseudes caecus is also a problematic species to compare with. The original description by Willemoes-Suhm (1875) is unusable for modern taxonomic comparisons. Furthermore, the type material is lost ( Sieg 1983:93) and the same author lists this species as belonging to genus Apseudes Leach, 1814 . A year later this species appear in a key to Leviapseudes ( Bäcescu 1984:34) and is attributed to Willemoes-Suhm, 1874 rather than 1875. Bäcescu’s (1984) key relies heavily on the presences and size of hypospherians, a character notorious unreliable ( Lang 1953), but apparently suggest that the female L. caecus have the pereopod 4 dactylus/unguis reduced to a claw (couplet 6–7) and also differs from the new species in having more articles in the inner rami of the antennule (couplet 34–35).

From all other species of the genus L. macaronesia can, apart from the pereopods 2–6 unguis apical curledleaf-shaped setae, be separated by the combination of: 1) cheliped carpus longer than basis and dactylus longer than fixed finger; 2) pereopod 4 dactylus/unguis not reduced to a claw; 3) pereopod 1 merus almost as long as basis.

Several appendages had ciliates attached to the cuticle ( Fig. 2 View FIGURE 2 J) as also seen in other deep-sea tanaids ( Larsen 2006).

Family Sphyrapodidae Gu ț u, 1980

Subfamily Pseudosphyrapodidae Gu ț u, 1980

Type genus. Pseudosphyrapus Guţu, 1980 Genus Pseudosphyrapus Gu ț u, 1980

Diagnosis (Modified after Guţu 1980, 1991, and Larsen 2005). Antennule with bi- or tri-articulate inner ramus. Antenna without squama/pseudosquama. Mandible with tri-articulate palp.

Male. Antennule with dense rows of aesthetascs. Maxilliped endite with distal outer corners ornamented. Pereopod 1 is longer and thinner than in the female and endite setation is different, in particular less setose than that of female. Cheliped dactylus with inner process. Merus and carpus longer than those of female. Pleopods with twice as many setae as in female.

Type species. Sphyrapus serratus G. O. Sars, 1882 .

Remarks. The character of the complete absence of a pseudosquama is stable in this genus. The presence of a tri-articulate mandibular palp is shared with Kudinopasternakia .