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Comprehensive Description

provided by Smithsonian Contributions to Zoology
Pardaliscella yaquina

DESCRIPTION OF FEMALE.—Upper lip short, broad, weakly excavate, lobes shallow and symmetrical; rostrum of medium size (Figure 38H), subacute, lateral cephalic lobes scarcely projecting forward, broadly rounded; right mandibular incisor with 3 large blunt teeth, 1 bifid, lacinia mobilis bifid to base, 1 spine in spine row and a setose ridge occurring proximal to it; left mandible with about 4 weak incisorial protuberances and other serrations, lacinia mobilis broad, minutely serrate, 2 spines in spine row, with setose ridge proximal to it; mandibular palp long, articles 2 and 3 equal to each other in length; lower lip like that of Pardaliscella boecki (Malmgren) (in Sars, 1895, pl. 143: fig. 2); inner plate of maxilla 1 small, bearing 1 long seta; lobes of maxilla 2 very thin (Figure 39X2); palp article 4 of maxilliped with 2 long inner serrations, inner plate thin, outer plate broad (Figure 39s); coxae 1–4 much broader than long, posterior margins with mammilliform hump, coxa 5 largest of all, coxa 7 with subacute mammilliform hump posteriorly; gnathopods stout like those of Pardaliscella Boeck, articles 5 and 6 equal in length to each other on gnathopod 1 but article 5 longer than 6 on gnathopod 2, both gnathopods densely setose but 2 more so than 1 on article 5, article 6 with palmar area forming oblique line occupying most of posterior margin of hand and densely setose and setulose-striate, undefined, many spines biplumose, dactyls more than 80 percent as long as hands, grossly serrate on inner edges; article 2 of pereopods 1–2 tumid in middle, much wider than article 3, articles 4–5 weakly expanded, article 5 much longer than 4!, dactyls only about 60 percent as long as sixth articles; second articles of pereopods 1–5 attached near middle of coxae, pereopods 3–4 successively slightly longer but pereopod 5 much longer than 4, pereopods 3–5 with increasingly broadened article 2, that on pereopod 5 subpyriform; pleonites 4 and 5 each with very small posterodorsal tooth; pleonal epimera 1–3 with sharp posteroventral tooth, that on epimeron 2 largest, epimera 1–2 lacking lateral ridge; each of uropods 1–2 with equal rami, uropod 3 with biarticulate outer ramus, inner ramus apically spinose and reaching scarcely past end of article 1 on outer ramus; telson cleft about 60 percent its length, each apex narrow, notched and bearing 1 long spine; article 1 of primary flagellum on antenna 1 not elongate.

HOLOTYPE.—USNM 127125, female, 3.3 mm. Unique.

TYPE-LOCALITY.—Station 11, 44°38.6′N, 125° 50.0′W, 400 m, 4 October 1962.

RELATIONSHIP.—Five species of this genus have been described, but I doubt that P. malygini Gurjanova belongs in this genus because of its very thin gnathopods; the right mandible has not been described in that species, and it differs from other species in the very large tooth of pleonal epimeron 3. The broadly rounded epimeron 3 of P. axeli Stebbing and P. boecki (Malmgren) characterize those species. Pardaliscella symmetrica J. L. Barnard, a sympatriot of P. yaquina, has a sharply quadrate epimeron 3 and the telson is cleft only halfway. Pardaliscella yaquina resembles P. lavrovi Gurjanova in epimeron 3 but differs from that species in the deeper cleft of the telson.

DISTRIBUTION.—Oregon, 400 m.
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bibliographic citation
Barnard, J. L. 1971. "Gammaridean Amphipoda from a deep-sea transect off Oregon." Smithsonian Contributions to Zoology. 1-86. https://doi.org/10.5479/si.00810282.61