Paralanceola anomala Barnard, 1930

Zeidler, Wolfgang, 2006, A review of the hyperiidean amphipod superfamily Archaeoscinoidea Vinogradov, Volkov & Semenova, 1982 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 1125, pp. 1-37 : 21-25

Paralanceola anomala Barnard, 1930 ( Figs 6 & 7 )

Paralanceola anomala Barnard, 1930: 398 –400, fig. 52. Hurley 1969: 33. Vinogradov et al. 1982: 47 –48, fig. 4. De Broyer & Jazdzewski 1993: 106.

Type material

The unique type of P. anomala is in the BMNH (1954.5.1.1.), on one microscope slide.

Material examined

The unique type, a male about 6 mm long, from the Pacific sector of the Antarctic [71°41S, 166°47W], ( Terra Nova Stn. 282), 0–1000 m, 7 Jan. 1913: one microscope slide of dissected appendages.

Diagnosis

Based on Barnard’s (1930) description and on examination of remains of the type. Males reach lengths of at least 6 mm. Head without rostrum. Eyes minute, consisting of four ocelli with crystal cones. Antennae 1; callynophore conical, similar in length to peduncle; with two small terminal articles, the terminal one more than twice as long as the preceding one, narrowing distally, tipped with one seta. Antennae 2; length 2.5–3.0x A1; seven (or 8?)­articulate; peduncular article elongate, relatively enlarged; flagellum very long, whip­like, consisting of six, very slender, elongate articles, the first is the longest and the terminal one is relatively short with three short setae terminally. Mandibular palp; length third article 1.3x articles 1 & 2 combined. Maxillae 1; palp with four, short, robust setae terminally and row of fine setae along inner margin; outer lobe with five robust setae, two slightly shorter than others. Maxillae 2; inner lobe with three, and outer lobe with four, relatively long, robust, dentate setae. Maxilliped; outer lobes with dentate inner margin; inner lobes slender, length about 0.5–0.7x outer lobes. Pereopods 3 & 4 similar in length, slightly shorter than P5 (>0.8x). Pereopod 6 similar in length to P7; both about 0.9x P5. Pereopods 5–7 with retractile and hooded dactyls. Uropod 1; peduncle reaching just beyond limit of peduncle of U2. Telson length about 0.7x peduncle of U3.

Description of holotype

Based on Barnards (1930) description and on examination of remains of the type. Male about 6.0 mm long. Entire cuticle with hexagonal markings. Head without rostrum or rostrum inconspicuous. Eyes consisting of four ocelli with crystal cones. Antennae 1; first peduncular article one­third longer than second; callynophore tapering abruptly, as long as peduncle. Antennae 2; peduncular article elongate (both broken with proximal part missing), more than 6x as long as wide, with row of fine setae on one margin; flagellum whip­like, consisting of six very slender, elongate articles; the proximal one the longest; the second almost half­length first; the third slightly more than half­length second; the fourth about half­length third; the fifth equal in length to third; the terminal one is relatively short, about 0.4x length fifth, with three short setae terminally and two subterminally. Mandibular palp; first article slightly shorter than second; length third article 1.2–1.3x articles 1 & 2 combined, with series of denticles ventrally for distal twothirds. Maxillae as in diagnosis. Maxilliped; length left inner lobe almost half outer lobe, but right inner lobe almost 0.7x length outer lobe (the difference perhaps attributable to distortion during mounting on microscope slide). Gnathopod 1; basis slightly shorter than carpus and propodus combined; merus densely denticulate on medial surface; propodus length about 0.8x carpus; merus carpus and propodus armed with relatively robust setae (some bifid and feathered); dactylus thin and straight, length 0.4x propodus, inserted subterminally. Gnathopod 2; (merus­dactylus missing from left); slightly longer and more slender than G1; similar to G1 except propodus slightly longer than carpus. Pereopods 3 & 4 (carpus­dactylus missing from left P3); similar in length and structure, slightly shorter than P5; basis slightly shorter than merus and carpus combined; merus and carpus similar in length, propodus slightly shorter, all armed with series of long setae on posterior margin. Pereopods 5–7 with retractile and hooded dactyls. Pereopod 5 the longest; basis with sharp anterodistal lobe, overlapping about half of ischium, length slightly more than merus and carpus combined; merus length 1.3x carpus; carpus as long as propodus; merus, carpus and propodus with series of short setae on anterior margin. Pereopod 6 slightly shorter than P5 but marginally longer than P3 or 4; basis length about 1.3x merus; merus length 1.6x carpus; propodus slightly shorter than carpus. Pereopod 7 similar in length and structure to P6 except propodus almost 1.3x length carpus. Uropod 1; peduncle with finely toothed margins for distal half; rami with both margins toothed; inner ramus similar in length to peduncle; outer ramus slightly shorter. Uropod 2; rami armed like U1; peduncle almost extends to limit of peduncle of U1; outer ramus slightly shorter than peduncle; inner ramus slightly longer than peduncle. Uropod 3 armed like U2; outer ramus slightly longer than peduncle; inner ramus slightly longer than outer, about 1.3x peduncle. Telson pointed; width marginally more than 0.7x length, as long as 0.75x peduncle of U3.

Remarks

Prior to this review, this was the only known species of Paralanceola . Two additional species are described here and distinguished from P. anomala as detailed under those species.

about 6.0 mm. Scale bar = 0.2 mm.

An examination of the remains of the unique type revealed a number of errors in the original description. In particular the flagellum of the second antennae is clearly jointed, consisting of six articles and the maxilliped has distinct, relatively long, inner lobes. The peduncular article of the second antennae is broken proximally as if the antennae were torn off during dissection, so it is impossible to determine if more peduncular articles were present. Otherwise the structure of the second antennae most closely resembles that found in mature males of Scina . However, most other characters are similar to those found in the two new species described here that have normal second antennae. These characters are also consistent with the family Archaeoscinidae rather than any other family of Hyperiidea .

Distribution

Known only from the type locality, the Pacific sector of the Antarctic [71°41S, 166°47W], near the Ross Sea, in 0–1000 m.

Figures

FIGURE 6. Paralanceola anomala, Pacific sector of Antarctic, BMNH 1954.5. 1.1. Holotype male, about 6.0 mm. A, dorsal view of head. Scale bars = 0.2 mm (A, A 2, Us), 0.1 mm (mouthparts).

FIGURE 7. Paralanceola anomala, Pacific sector of Antarctic, BMNH 1954.5. 1.1. Holotype male,