dcsimg

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Lubbockia wilsonae

Lubbockia aculeata.—Vervoort, 1951, p. 151; 1957, p. 148.

MATERIAL STUDIED.—1 female in each of samples 6 and 17; body lengths 2.70 and 2.75 mm (holotype). Holotype on slide deposited in the United States National Museum (123515).

FEMALE.—Body (Figures 11–12) slender, urosome slightly longer than prosome. Rostral area moderately well developed. Urosome with small spinules in distinctive patterns on ventral posterior margin of each segment (Figure 13). Segment of leg 5 with minute spinules on dorsal and ventral surfaces. Genital apertures lateral, each encircled with ring of sclerotization from which leg 6 protrudes.

Caudal rami about one-half the length of anal segment. Dorsal surfaces of the prosome and urosome bear minute setules, the more conspicuous ones as indicated in Figure 11.

First antenna (Figure 14) 6-segmented; less than one-half the length of cephalosome. Armature: segment I–4; II–6, 1 esthete, 1 spine; III–4; IV–3, 1 esthete; V–2, 1 esthete; VI–6, 2 esthetes.

Second antenna (Figure 15a) subprehensile, 3-segmented; 2 subapical setae, 1 nude and 1 with row of hairs on concave edge; armed terminally with 3 claws, 1 twice the width of the other 2, and 1 seta with row of hairs.

Labrum (Figure 15b) with 2 posteroventral lobes bearing marginal spinules.

Mandible (Figure 16a) with posterior margin of base sclerotized and followed distally by slightly curved element with row of graduated hairs on outer edge. Large U-shaped central area of surface sclerotization encircles wide, flat, hirsute seta and 2 clusters of hairs, 1 long and 1 short. Second wide hirsute seta on posterior distal margin of surface sclerotization. Mandible terminates in long blade with row of graduated, obtuse, scalelike denticles on outer margin.

First maxilla, with the middle seta broken from larger lobe, appeared to be similar to Giesbrecht’s (1892, pl. 48, fig. 9) illustration for L. aculeata.

Second maxilla (Figure 16b) with 1st segment expanded and bearing 2 clusters of fine hairs. Second segment with small setule on outer margin and bladelike seta on posterior surface; inner margin with plumose, lashlike seta with row of long hairs arising near the base; distal part of segment bearing a strong nude element; a seta, fringed with a row of spinules grading to hairs, arises near the base of this element. A thin, flat element arises at the base of the seta; one preparation suggested that additional thin, flat elements are hidden by the first.

Maxilliped (Figure 17) with patch of small denticles on basal segment; anterior margin of 2nd segment with 5 or 6 triangular spines and short and long row of small denticles. Number and pattern of spines and denticles varied between the 2 specimens, as well as between right and left maxilliped; 1 specimen with 6 triangular spines on left 2nd segment of maxilliped and 5 on right. Third segment short and unarmed; terminal claw with 1 small proximal denticle and row of dentiform spines on concave margin, number varying between the 2 specimens.

Legs 1–4 (Figures 18–19) with trimerous rami; endopod and exopod spines with serrate, hyaline flanges, except long apical spine of exopods has exterior flange and interior feathered margin. Armature of swimming legs:

Leg 5 (see Figure 13) with free segment one-fourth the length of genital segment and bearing patches of minute surface spinules. Armature consisting of 2 flanged setae, the inner nearly twice the length of the outer. Outer distal margin of segment with small process.

Leg 6 (see Figure 13) probably represented by well-developed segment protruding from genital aperture. Segment with chitinous plaque on ventral surface and 2 nude terminal setae of unequal length.

It is a pleasure to name this species in honor of Mildred Stratton Wilson, Anchorage, Alaska, in recognition of her many contributions to the study of North American copepods and in gratitude for her guidance and inspiration to the authors.

Lubbockia wilsonae is close to L. aculeata Giesbrecht, 1891, but can be distinguished without dissection by differences in legs 5 and 6 and proportional lengths of urosomal segments.

Vervoort (1951, 1957) identified an Antarctic species of Lubbockia as L. aculeata, but mentioned that the 1st segment of the maxilliped on his specimens had, instead of 1 large spine, a cluster of small spines. Dr. W. Vervoort kindly sent us a female specimen, 2.60 mm, from British, Australian and New Zealand Antarctic Research Expedition station 44. We have identified the specimen as L. wilsonae, extending the distribution record from the Gulf of Alaska to the Antarctic Ocean. This specimen has been deposited in the United States National Museum (277051).
license
cc-by-nc-sa-3.0
bibliographic citation
Heron, Gayle A. and Damkaer, David M. 1969. "Five species of deep-water cyclopoid copepods from the plankton of the Gulf of Alaska." Smithsonian Contributions to Zoology. 1-24. https://doi.org/10.5479/si.00810282.20

Biology

provided by World Register of Marine Species
from deep water in plankton
license
cc-by-4.0
copyright
WoRMS Editorial Board
contributor
Ju-shey Ho [email]