“Ammothea gordonae, new species Fig. 4
Material examined. Eltanin: 27-1873 (one holotype male with eggs, USNM 234621, one female (paratype, USNM 234622)), 27-1924 (one male, one female, one juvenile (paratypes, USNM 234623)).
Other material. Eltanin: 32-1996 (one male). Islas Orcadas: 876-129 (one juvenile).
Distribution. This species is known from the type locality, the Ross Sea off Cape Mare and off the Ross Ice Shelf front, in 348-732 m. It is also known in other material listed above from the vicinity of the South Orkney Islands in 225-234 m. This disparity in collecting localities lacks any logical explanation except to suggest an artifact in collecting effort. Information about the bottom configuration and fauna in each of these localities is lacking which might have provided a type of bottom or fauna.
Diagnosis. Size moderately small for the genus. Trunk with large dorsal ridges at segmentation lines, ridges partly curled over, without conspicuous conical tubercles. Lateral processes large, crowded, separated only by narrow intervals, with low bulbous dorsodistal tubercles. Ocular tubercle small, slightly taller than wide, not taller than trunk ridges, eyes of typical size. Proboscis long, almost cylindrical with slight distal constriction just before slightly bulging tip. Abdomen short, erect.
Palp 9-segmented, typical. Oviger segments short, with 3 reduced terminal segments. Legs with moderately dense pile of tiny setules, without long spines or setae. Propodus without long heel spines but with 4 long sole spines, the third distal spine twice as large as the other 3.
Description. Size moderately small, leg span of holotype is 106 mm. Trunk robust, lateral processes closely spaced but not touching, almost twice as long as their diameters, dorsomedian trunk with narrow ridges at segment posteriors, ridges slightly rolled or laterally creased, without conspicuous broad median tubercles. Small broad tubercle over abdomen insertion. Lateral processes with paired low dorsodistal ridges not large enough to be tubercles but armed with a fringe of tiny setules. Ocular tubercle twice as tall as its width, as tall as dorsomedian ridges, with rounded tip, eyes moderately large, well pigmented. Cephalic segment, anterior and lateral to ocular tubercle, provided with low rounded tubercles over insertion of both chelifores. Proboscis long, about 0.85 trunk length, a cylinder with slight tapering distally to slight inflation at tip, lips rounded. Abdomen moderately short, arising from low tubercle at base, carried obliquely erect, armed with tiny dorsal and ventral setules.
Chelifore scapes short, no longer than first 2 palp segments, club-shaped, armed with tiny setules. Chelae atrophied, with a tiny bump as segmented movable finger and another tiny papilla as the immovable finger, with tiny setules on palm.
Palps 9-segmented, sparsely armed with tiny setules only. Fourth segment longest, about 1.2 times longer than second. Segments 5-9 each about twice longer than its diameter with diameter slightly increasing distally.
Ovigers moderately short, armed with fields of tiny setules, second segment equal to fourth, fifth shorter, well curved. Sixth and seventh of same diameter as first 5 while terminal 3 segments of narrower diameter and much shorter. Eighth segment articulated anaxially with seventh. Eighth with few ectal setules, ninth and tenth even narrower, with vew very short spines distally on terminal segment which has blunt tip.
Legs clothed in tiny setules. Second tibiae the longest segment with femora little shorter. Cement gland orifice a tiny slightly raised pore well proximal to dorsodistal femur tip. Tarsi very short, with single ventral spine. Propodi moderately short, not curved, armed with 4 sole spines, spines 1, 2, and 4 of equal size and spine 3 much larger, without heel spines. Claw moderately short, auxiliaries slightly more than half main claw length.
Measurements of holotype (in millimeters). Trunk length [chelifore insertion to tip fourth lateral processes], 11.69; trunk width [across second lateral processes], 8.81; proboscis length, 9.25; abdomen length, 3.53; third leg, coxa 1, 2.38; coxa 2, 4.11; coxa 3, 3.21; femur, 11.69; tibia 1, 9.87; tibia 2, 12.38; tarsus, 0.59; propodus, 3.0; claw, 1.44.
Etymology. I take great pleasure in dedicating this new species for the late Isabela Gordon, who once very appropriately described herself to me as a "wee Scot lass" and who contributed so much excellence to our knowledge of Antarctic Pycnogonida in particular and to knowledge of so many groups of Crustacea in general.
Remarks. This species apparently belongs to the proposed subgenus Ammothea of Fry and Hedgpeth [1969, p. 731, but this should not be interpreted as giving explicit recognition to this ill-defined group of proposed subgenera. Using their diagnoses, there is no clear way to separate the subgenera assigned to most of the Antarctic species, so the designations have little meaning except to provide another level of artificial splitting which is, in my opinion, not needed in this genus.
In keeping with Fry and Hedgpeth's suhgeneric definition, the new species has massive trunk ridges which are semiconical at the median line, the eye tubercle is more of a blunt cylinder than bluntly conical and taller than its basal diameter, the proboscis is very long but not straight, although the distal tip is bulbous, the propodi are all similar, and the genital pores are on the posterior four second coxae.
The proboscis of this species does not resemble that of any other known Antarctic species, and its taper terminating in a slightly swollen tip distinguishes it from any other Ammothea species. Most other characters of this new species are typical of the genus except for the propodi which have major spines not at the heel as typical, but placed toward the distal end of the sole. The spines are arranged, counting from proximal to distal, as two moderately short spines, followed by one spine twice as long, and another shorter spine distal to the large spine, with very short tiny spines mixed between and proximal to the major spines. This arrangement is probably closest to the anterior four propodi of Ammothea spinosa, but this is one of the species with differing propodi on the anterior and posterior four leg pairs, and it has many other differences, including the very short auxiliary claws which are not in agreement with this new species.” (Child 1994, p.20-22)
