Lepechinella victoriae, Johansen & Vader, 2015

Johansen, Per-Otto & Vader, Wim, 2015, New and little known species of Lepechinella (Crustacea, Amphipoda, Lepechinellidae) and an allied new genus Lepesubchela from the North Atlantic, European Journal of Taxonomy 127, pp. 1-35 : 23-28

Lepechinella victoriae sp. nov.

urn:lsid:zoobank.org:act:AD61D708-1965-42F1-9352-FC42969F9EC7

Figs 13–16

Diagnosis

Eyes absent. Body sparsely covered with spines and setae. Lateral processes of head acute, as long as rostrum. Inner lobes of lower lip well developed. Mandible palp article 1 half the length of article 3. Maxilliped palp 4-articulate. Posterior legs long and very slender. Anterodistal part of coxae 3–5 strongly produced. Posterodistal corner of coxa 7 acute. Gills proximally pleated. Posterior part of pleon segments 1–4 each with one dorsal tooth.

Etymology

The species is named after POJ’s first grandchild.

Material examined

Two specimens of Lepechinella victoriae sp. nov. were collected at station 83.06.5.1, in the North East Atlantic, south of Iceland. The in situ temperature was measured to 2.7 o C. The type material of Lepechinella victoriae sp. nov. is deposited in the collections of Zoological Museum in Bergen.

Holotype

Adult female, registration no. ZMBN 99134 , 5.5 mm, station 83.06.5.1, 61 o 38.2’N, 16 o 27.7’W, 2355 meter depth, 5 Jun. 1983.

Paratype

Female, registration no. ZMBN 99135, 4.5 mm, date and position as for holotype.

Description

Holotype Female, 5.5 mm.

BODY. Sparsely covered with short setae, mainly situated mid-dorsally. Peraeon segment 1 with 2 teeth, peraeon segments 2–7 each with one mid-dorsal tooth. Coxal plates short, decreasing in length posteriorly.

HEAD. Subequal to peraeon segments 1–2; rostrum acute, horizontal, length 0.5x antenna 1 peduncle article 1; lateral processes acute, as long as rostrum; eyes absent or at least indistinct in alcohol. Antenna 1,

peduncle article 1 thicker than articles 2 and 3 and 0.5x length of peduncle article 2; peduncle article 3

is 0.4x article 1; scattered long setae on peduncle article 2 and distally on peduncle articles 1 and 3; flagellum twice as long as peduncle articles 1–3 combined; flagellum 30-articulate. Accessory flagellum short, consisting of one article with two long apical setae. Antenna 2 is slightly longer than antenna 1. Antenna 2, peduncle articles 1–3 combined 1/3 of article 4; peduncle article 4 is 0.6x article 5; flagellum longer than peduncle article 5; flagellum 20-articulate.

MOUTHPARTS. Upper lip oval; lower lip inner lobes large, extending to 3/4 of outer lobes; mandible incisor and lacinia mobilis of subequal length, gaping at 45 o angle; 6–7 accessory spines; molar round, with ragged margins; mandible palp article 1 is 0.5x article 3; mandible article 2 is 3x article 3; mandible

article 2 and 3 with 10 and 6 setae, respectively. Maxilla 1, inner plate stout, 0.5x outer plate, with 2 apical plumose setae; outer plate with 8–10 strong spine teeth; palp 2–articulate, article 2 distally expanded, with 7 short and 1 long distal spines. Maxilla 2, inner plate broad and slightly shorter than outer plate, with short marginal and long apical setae; outer plate with 16 long apical setae. Maxilliped, inner plate half the length and width of outer plate; outer plate with 11–12 long spine teeth on inner margin and apically, increasing in length distally; palp 4-articulate; outer plate reaches article 3 of palp; article 2 slender and by far the longest, with long setae on inner margin; long setae on article 1–3.

PERAEON. All legs long and very slender. Peraeopods 5–7 longer than peraeopods 3–4; peraeopods 3–7 much longer than gnathopods. Gnathopod 1, subchelate and coxal plate 1 biacuminate, the anterior tip 1.5x posterior; propodus shorter than carpus; basis longer than merus and carpus combined; propodus tapering distally; dactyl curved and 0.5x propodus; 3–5 groups of setae on anterior and posterior part of propodus; palm serrulate. Gnathopod 2 subchelate and longer than gnathopod 1; coxal plate 2 tapering to an acute tip; coxal plate 2 with long marginal setae; carpus 1.6x propodus; basis 1.3x carpus; basis with long setae on posterior margin; carpus and propodus with long setae on both margins; dactylus slender and curved; dactylus shorter than 0.5x propodus; palm serrulate. Coxal plate 3 asymmetric, with long acute anterior process; peraeopod 3, carpus and propodus of about equal length, shorter than merus and

basis; dactyl lanceolate, as long as propodus; merus and carpus with long marginal setae. Coxal plate 4 asymmetrically bifid; with long acute anterior process and short blunt posterior process; peraeopod 4, similar to peraeopod 3, but propodus shorter than carpus. Coxal plate 5 rectangular, but with long acute slender anterior process; peraeopod 5, basis and carpus about of equal length, merus much shorter; dactyl lanceolate, slightly shorter than propodus; all articles setose. Coxal plate 6 much wider than high, posterodistal corner subacute, with short setae; peraeopod 6, carpus longer than propodus; merus shorter than either; dactyl lanceolate, slightly shorter than propodus. Coxal plate 7 wider than high, posterodistal corner acute, with short setae; peraeopod 7, basis and carpus of about equal length; propodus shorter, merus much shorter; dactylus lanceolate, slightly shorter than propodus.

PLEON. Subequal in length to peraeon. Pleon segments 1–3 each with one large dorsal tooth at posterior margin; epimeral plates 1–3 similar, with well-developed posterodistal tooth. Urosome shorter than pleon. Urosome segment 1 with large, curved tooth on mid-dorsal margin; urosome segments 2 and 3 fused. Uropods long and slender. Uropod 1, peduncle about as long as outer ramus; inner ramus 0.8x outer ramus; peduncle with long marginal setae on outer margin, and two distal spines; rami with short spines. Uropod 2, peduncle shorter than inner ramus, but longer than outer ramus, which is 0.7x inner. Uropod 3, peduncle short and wide, about 1/6 of rami; shorter ramus 0.9x longer, both with long marginal setae. Telson cleft 40 % of total length, with the halves gaping, with acute tips, each with one marginal and one long apical setae, the latter subequal to the length of the telson.

Remarks

L. victoriae sp. nov. lacks the distinct additional dorsal humps / teeth found in L. schellenbergi , L. norvegica sp. nov. and L. arctica . Peraeopod 4 carpus longer than propodus, while it is the reverse in the three above mentioned species. The anterodistal lobe on coxae 3–5 is strongly elongated. The gills are proximally pleated. As in L. schellenbergi uropod 2 outer ramus is 0.7x inner, while the ratio is 0.8x in L. norvegica sp. nov. The rostrum is subequal in length to eye lobes, innerlobes of lower lip relatively large as in L. grimi and mandible palp article 1 is half the length of article 3.

Figures

Fig. 13. Lepechinella victoriae sp. nov., holotype, ♀. A. Habitus. B. Head. C. Spine on head. D. Left Gn1. E. Plumose setae. F. Left Gn2.

Fig. 14. Lepechinella victoriae sp. nov., holotype, ♀. A. Right Ep1. B. Right Ep3. C. Right Ep2. D. Right and left Mx1. E. Left and right Mxp. F. Right mandible. G. Left Mx2. H. Upper lip. I. Lower lip. J. Gill of P4.

Fig. 15. Lepechinella victoriae sp. nov., holotype, ♀. A. Left P6. B. Tooth of peraeon segment 7. C. Female A1. D. Accessory flagellum. E. Female A2. F. Left P3.

Fig. 16. Lepechinella victoriae sp. nov., holotype, ♀. A. Left P5. B. Left P4. C. Right P7. D. Right U1. E. Right U2. F. U3. G. Telson.