Bamberene dorsospina ( Clark, 1963 )

Staples, David A., 2014, A reassessment of the pycnogonid genus Stylopallene (Arthropoda, Callipallenidae) with description of a new genus, Memoirs of Museum Victoria 72, pp. 121-129 : 127

Bamberene dorsospina ( Clark, 1963)

Zoobank LSID. http://zoobank.org/ urn:lsid:zoobank.org:act:

FD54384E-DF6A-4763-B1A9-BCC93C4C89F7

The specific name is here amended to the correct gender ending.

Stylopallene dorsospinum Clark, 1963: 38-40 — Staples, 1997:

1055

Material examined. Australia, AM P42848 East of Long Reef , New South Wales 33° 43'S, 151° 46'E, K85-21-08, 174 m, FRV Kapala, 12 Sep 1985, 1 male, 1 female, 2 subadults . AM P43312 off Sydney , NSW, 33° 46'S, 151° 43'E, stn K77-23-01, 176m FRV Kapala, 12 May 1977, 2 males, 2 subadults, 1 juv. NMV J62425 Waterloo Bay, Wilsons Promontory , 10 m, D.A. Staples, 28 Mar 1981, 1 female . NMV J48962 New South Wales, off Nowra , SLOPE 1 (34° 59. 31'S, 151° 05. 56'E), 204m , WHOI epibenthic sled, substrate coarse shell, coll. G.C.B. Poore et al., 14 Jul 1986. 1 subadult .

Distribution. Port Phillip, Victoria to Botany Bay, New South Wales. Depth 1- 204 m.

Remarks. Leg span 15-20 mm. Clark’s description of S. dorsospinum is based on three females, a damaged male and two juveniles trawled off Twofold Bay and Wata Mooli, New South Wales. Examination of additional material held in the Australian museum and Museum Victoria has enabled further observations to be recorded. The ocular tubercle has two dorsal papillae. The proboscis is setose distally, the setae surrounding the jaws being much shorter but denser than the proximal setae so much so that the jaws are obscured when closed ( fig. 4F). The jaws appear to be soft and flexing, petallike when open. The arthrodial membrane at the base of the proboscis is broad enabling the proboscis to move through 45° to a vertical position. The movable finger of the chela has an outward bend in the mid-region which is most evident in ventral view ( fig. 4F). Near the tip of the finger is a short lip on the inner margin upon which the tip of the immoveable finger comes into contact when the chela is closed. The lip gives the tip of the finger a slightly thickened, bifurcate appearance. The oviger is ten-segmented and a terminal claw is completely lacking ( fig. 4D). In the male specimens examined the surfaces of segments 7-10 are covered in filaments which obscure the number of compound spines present. The terminal ‘boss-like structure’ noted by Clark on the female oviger is not present but several simple (some tiny) spines originate from the surface, compound spines on segments 7-10 are slender with one or two-pair of lateral teeth. The spine formula is variable between specimens but spines are either absent or few (1-4). Several simple spines are also present. A conical swelling on the outer surface of segment 4 in both sexes is probably the site of a gland opening. In the females examined it varies in size between specimens.

In males, femoral cement glands are represented by two pale swellings on the lateral margin of the posterior surface of all legs. Gland openings are obscure ( fig. 4B). Spines broken off the dorsodistal part of the femur and elsewhere leave a hollow in the basal tubercle giving the incorrect impression that these are gland ducts. Females are less spinous than males; the spine-tipped tubercles on the chelifore scape are absent and those on the femur are less abundant.

Should Bamberene dorsospina adopt the same (dorsal to ventral) mating position as do species of Meridionale ( Staples 2014, fig. 4A) and Stylopallene ( fig. 2E), then the presence of mid-dorsal trunk processes would be an encumbrance to the transfer of eggs. This suggests an alternative mating position for this species and perhaps explains the absence of a proximolateral chelifore scape process. In a group of otherwise smooth species, the presence of dorsal processes may be of evolutionary significance. In the light of this observation the standing of Austropallene cristata ( Bouvier, 1911) within Austropallene may need to be reconsidered.

The host substrate and colour markings of S. dorsospina are not recorded and evidence of body markings has not persisted in the specimens examined.

Larval and juvenile forms. The protonymphon is attached to the male oviger by a single thread extending from one chelifore. A gland duct is not evident. The proboscis is not completely developed in the early stages. At the stage where the third pair of legs is present but still incompletely developed, the distal tubiform part of the juvenile proboscis is absent. At this stage the mouth is wide and open. The juvenile chela is welldeveloped, fingers strongly bowed and gaping.