Revision of the crab genus Garthambrus Ng, 1996, with the description of two new genera and discussion of the status of Tutankhamen Rathbun, 1925 (Crustacea: Brachyura: Parthenopidae)
Author
Mclay, Colin L.
text
Zootaxa
2009
2122
1
50
journal article
10.5281/zenodo.188125
c573d381-a5e4-4bb5-8c6b-5fd1eeeaf2ce
1175-5326
188125
Zarenkolambrus epibranchialis
(Zarenkov, 1990)
comb. nov.
(
Figs 18
C,D, 20)
Heterocrypta epibranchialis
Zarenkov, 1990: 232
, fig. 10. – Parin
et al.
1997: 163 (list).
Type
material.
SYNTYPES
:
2 males
CL
4.8 mm
, CL 5.0 mm, Southeast Pacific Ocean. Near
Sala
y Gómez and Utes seamounts, stn 2003, 330–
350 m
, RV
Professor Shtokman
; 1 damaged specimen, Igolnaya Seamount, stn 2007, 290–
310 m
, RV
Professor Shtokman
: Data after Zarenkov (1990). None of these specimens were examined.
Diagnosis.
Carapace finely granular, not spinose, without deep lacunae; supra-orbital region without spines. Tubercles on protogastric, mesogastric, epibranchial, mesobranchial and cardiac regions not fusing together to form smooth ridges or plates. Rostrum long, about one-quarter carapace length. Epibranchial margin teeth flat, edges irregular. Sub-orbital spine produced, tip extending beyond anterior outer corner of antennal article 2. Outer margins of cheliped merus and carpus not tuberculate, appearing entire. P5 upper margin of merus, carpus and propodus dentate.
Distribution.
Southeastern Pacific (
290–350 m
) and Nazca and
Sala
y Gómez submarine ridges, Eastern Pacific (Zarenkov, 1990).
Remarks.
The diagnostic features, originally given in Russian by Zarenkov (1990) and translated by A. Anker, are as follows: “whole body surface finely granular. Rostrum triangular, apex rounded, sides slightly concave. Posterior edge of orbits with small notch. Border of branchiostegal region with 6–8 irregular, flattened teeth. Lateral border of carapace continued by somewhat rounded process. Posterior epibranchial border of carapace separated from posterior border by some teeth. Dorsal surface of carapace inflated in the middle and bears some feebly marked epibranchial keels. Telson triangular, abdominal segment 6 with large/ tubercle in middle of anterior border. Shape of sixth segment trapezoidal. Eye stalk minutely tuberculate. Basal article of antenna with sub-terminal process. Deep depression of antennule not completely separated from orbit by rostral process.
Third maxilliped ischium and merus granular, anterior borders depressed. Lateral anterior part of merus slightly expanded.
Cheliped cutting edges not regular. Upper surface of dactylus with teeth and large process near articulation. Three flattened teeth on upper surface of propodus with large process near carpus. Dactylus also with process. Cheliped merus with one shallow process (tooth), with small process (tooth) in the middle, also four on the inner side.
Meri of P2–P5, have 5–7 granules/teeth on anterior margin. Same kind of teeth also present on posterior margin of P4 and P5. P2 and P3 without teeth on posterior margin. Lower surface of carpus smooth but upper surface granular (P2–P5). Propodus of P2–P5 granular on both margins. Dactylus straight; surface smooth.”
It is clear from the text and the illustration (Zarenkov, 1990: 233, fig. 10) that this species does not belongs in the genus
Heterocrypta
Stimpson, 1871
, or similar genera like
Cryptopodia
H. Milne Edwards, 1834
, or
Furtipodia
Tan & Ng, 2003
. It does not resemble any of these genera because of the differences in carapace shape. The posterior lateral portion of the carapace of
Z. epibranchialis
is clearly not expanded to cover the ambulatory legs as in
Cryptopodia
. In addition,
Z. epibranchialis
has prominently produced lateral teeth, which are absent in
Heterocrypta
,
Cryptopodia
and
Furtipodia
.
Although we did not examine any specimens of this species, illustrations of this species, although somewhat schematic, show that it has several unique features. Its most prominent feature is the long rostrum, which is about one quarter of the entire carapace length. We believe that the long rostrum is more apparent than real and is the result of the orientation used by Zarenkov (1990) for his illustration (
Fig. 10
). The other
Zarenkolambrus
species,
Z. minutus
has a much shorter rostrum. The gonopods shown in
Fig. 6
E & F are probably those of an immature male because the G2 flagellum is not twisted, so the exact adult gonopods are yet to be determined.
Zarenkolambrus epibranchialis
is only known from two small males (CL 4.8–5.0 mm) and one damaged specimen.