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Classification


USNM 87608.2896

Bathymetric Specimen Dispersal

2 individual specimens found for Boehmia dubia.

Boehmia dubia Hedgpeth  Species

Synonymy

Original Description
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“BOEHMIA DUBIA, new species FIGURE 18

Holotype (U.S.N.M. No. 87608): 1 female (?), station 104, off Cape Royds, Ross Island, 58 fathoms, January 29, 1948.

Paratype (U. S. N. M. No. 87609): 1 juvenile.

This little beast is an ambiguous anomaly, and on the basis of these specimens alone it cannot be safely referred to an established genus. It is possible that the type specimen is a penultimate molt stage and that ovigers will appear in the adult. If future collections demon­strate that the absence of ovigers is a constant character in the females of this species, it must be removed from the Ammotheidae altogether, or considered an aberrant member of the family. It would then have close affinities with the Phoxichilidiidae, although the possession of well-developed ammotheid palpi would impair the definition of that family. It seems hardly justifiable even to erect a new genus for this form, although its well-developed auxiliary claws separate it from the species referred to Boehmia. The chelifores and palpi, however, as well as the general aspect of the creature, suggest that genus.

Description—Trunk oval in outline, lateral processes distinctly separated, trunk segments marked off by well-developed annular divi­sions. Cephalic segment projected forward, with several sharp coni­cal processes at the outer anterior corners over the insertion of the chelifores. There are also conical or thornlike processes on the corners of the lateral processes and the first coxae. The eye tubercle is a tall, pointed, narrow cone, with well-developed eyes about halfway between the base and apex. The first three trunk segments each bear a slender conical process about as tall as the eye tubercle near the posterior margins of the segments, which are actually prolongations of the dorsal portion of the annular swellings which mark off the segments. Proboscis curved downward, tapering to a blunt, rounded point, cylindri­cal at the base. The chelifores and palpi arise from a rim around the base of the proboscis.

Chelifore: 2-jointed, the scape armed with a thick-set group of thornlike processes on the dorsal distal half. Chela slightly larger than scape, fingers bowed, without teeth, tips overlapping. There is a sharp process on the outer margin of the palm over the insertion of the dactylus.

Palpus: 7-jointed, first and third short, subequal, second and fourth long, second about three-fourths as long as the fourth. Three terminal joints short, fifth and seventh subequal, sixth slightly longer. The palpus originates directly below the chelifore.

Ovigers: Absent.

Third leg rather stout, first and third coxae subequal, second slightly longer. There are several spurs on the first, and one or two on the second coxa. Femur plain, slightly curved, subequal to first tibia. Second tibia longer than first. Tibiae armed dorsally with sharp spurlike processes; and bearing short spines along the ventral surfaces. Tarsus short, cuplike, with a large spine dorsally and a larger one ventrally accompanied by several small spines. Propodus slightly arched, sole armed with one very large spine proximally and two smaller ones near the middle, and a much smaller one near the base of the claw. Claw almost as long as propodus, curved. Auxiliary claws about a third as long as the terminal claw.

Measurements of Holotype—As follows

Mm.

TRUNK

2.5

ABDOMEN

0.6

PROBOSCIS

Ca. 1.0

WIDTH, SECOND LATERAL PROCESS

1.5

CHELIFORE:

Scape

0.4

Chela

0.5

THIRD LEG:

Coxae

0.09

Femur

1.25

First tibia

1.25

Second tibia

1.5

Tarsus

0.1

Propodus

0.7

Terminal claw

0.5

Remarks.—As already noted above, this is an ambiguous curiosity. The holotype specimen appears to be a female. I could find no genital pores, and the specimen is evidently immature. The other specimen is about three-fourths as large, with only the first three pairs of legs fully developed, the fourth pair being represented by single jointed buds. Like the larger specimen it has no trace of ovigers. The well-developed palpi and propodus of both individuals suggest that the holotype specimen is a relatively late stage.” (Hedgpeth, p.155-157)

Specimens

Type Status Catalog No. Date Collected Location Coordinates Depth (m) Vessel
Holotype 87608 Images Available 1/29/1948 Ross Sea   106  
Paratype 87609 1/29/1948 Ross Sea   106  

View additional taxa  View all species collected at same locations as Boehmia dubia