“Bathypaguropsis yaldwyni McLaughlin, 1994
(Figs 37b, d, f; 38b, d)
Pagurid 'smooth apricot': Schembri 1982b: 871; Schembri & McLay 1983: 29, figs 7a, b.
Bathypaguropsis yaldwyni McLaughlin, 1994: 471, figs 1A, 2, 3; 1997: 541.
TYPES:
Holotype: female (sl = 10.4 mm), CM Stn 149, NMNZ Cr 8067.
Paratypes: 1 male, 2 females (sl = 5.2-5.9 mm), 22 km E Aldermen Islands, 410-415 m, 12.87, NMNZ Cr 7523; 1 female (sl = 3.4 mm), Stn BS 842, NMNZ Cr 8129; 1 male (sl = 8.3 mm), Stn BS 741, NMNZ Cr 8151; 1 male (sl = 11.2 mm), CM Stn (a), NMNZ Cr 7519; 1 female, 1 ovigerous female (sl = 9.5, 9.6 mm), CM Stn (b), NMNZ Cr 7517, Cr 7518; 1 ovigerous female (sl = 9.8 mm), CM Stn (c), NMNZ Cr 7514; 2 males (sl = 9.4, 10.6 mm); CM Stn (d), NMNZ Cr 7513, Cr 7515; 1 male, 1 ovigerous female (sl = 10.0, 9.0 mm), CM Stn 145 NMNZ Cr 8118; 1 ovigerous female (sl 10.5 mm), CM Stn 149, NMNZ Cr 7516; 1 male (sl = 8.5 mm), JC Stn D4, NMNZ Cr 8105; 1 male (sl = 4.4 mm), JC Stn J06/048/81, NMNZ Cr 8087; 2 males (sl = 5.4, 7.6 mm), NPC Stn T3, NMNZ Cr 8027; 1 male (sl = 5.8 mm), NPC Stn "a", NMNZ Cr 8080; 1 male (sl = 6.2 mm), NPC Stn "b", NMNZ Cr 8214; 1 male, 1 female (sl = 10.0, 8.2 mm), CM Stn 145, USNM 267573.
TYPE LOCALITY: Solander Trough, CM Stn 149, 46°30'S, 165°14.4'E, 545-573 m.
OTHER MATERIAL EXAMINED:
NZOI Stns: A910,1 male (sl = 10.2 mm); B315, 1 male, 1 female (sl = 3.1, 3.5 mm); C646, 1 male (sl = 2.8 mm); D176, 2 males (sl = 11.1, 12.2 mm); D870, 1 male moult (sl = 12.3 mm); D871, 1 male (s1 = 13.2 mm), 1 female (sl = 13.7 mm); E79, 1 ovigerous female (sl = 12.4 mm); E728, 1 male (sl = 6.0 mm); E803, 5 males, (sl = 4.0-6.8 mm) 2 females (sl = 8.2, 9.7 mm), 2 ovigerous females (sl = 8.4, 9.9 mm); E822, 3 ovigerous female (s1 = 8.2-9.9 mm); E827, 1 female, 1 intersex (sl = 8.0, 9.5 mm); 1 male (sl = 8.2 mm); E907, 1 female (sl = 4.3 mm); G935, 1 male (sl = 9.6 mm); G938, 1 male (sl = 6.4 mm); 17, 2 males (sl = 6.0, 7.1 mm), 1 female (sl = 5.5 mm); 132, 1 male (sl = 6.8 mm), 1 female (sl = 6.1 mm); 1364, 1 male (sl = 9.3 mm); 1365, 1 ovigerous female (sl = 6.0 mm); V418, 1 male (sl = 8.4 mm); Z2363, 2 males (sl = 6.5, 8.1 mm), 1 female (5.7 mm), 1 ovigerous females (sl = 7.9 mm); Z8259, 2 ovigerous females (sl = 7.9, 9.2 mm); Z8270, 1 female (sl = 6.7 mm), NMHN Pg 5890; Z9000, 1 male (sl = 7.9 mm), 1 female (sl =10.2 mm), 1 ovigerous female (sl = 6.8 mm); Z9003, 1 male (sl = 6.2 mm), 2 ovigerous females (sl = 5.8, 6.1 mm).
NMNZ collections: Bay of Plenty, coll. J. Costello, 13.6.62, 457 m, 1 male (sl = 5.4 mm), MNHN Pg 5889; Bay of Plenty, 1994, 457 m, 1 male (sl = 8.7 mm), Cr 9601; 1 male (sl = 5.4 mm) Cr 9602; Stn BS419, 1 male (sl = 8.6 mm), Cr 9603; BS 783, 1 male (sl = 6.9 mm), Cr 9604; CM Stn 146, 2 ovigerous females (sl = 8.4, 10.2 mm), Cr 9605; CM Stn 146, 2 ovigerous females (sl = 8.4, 10.2 mm), Cr 7508; CM Stn154, 2 males (sl = 9.4, 11.1 mm), Cr 7530; VUC "a", 1 female (sl = 4.6 mm), Cr 9606.
NZMD collections: Haul 5, 1 ovigerous female (sl = 5.0 mm), NMNZ Cr 9607; Haul 20, 1 female (sl = 4.6 mm), NMNZ Cr 9608; Haul 27, 1 male (sl = 7.4 mm), NMNZ Cr %09; Haul 31, 1 female (sl = 8.6 mm), NMNZ Cr 9610.
PMBS collections: Stn Mu 67-61, 1 female (sl = 8.1 mm), 1 ovigerous female (sl = 8.5 mm); ail Mu 74-95, 1 male (sl = 4.7 mm); Stn Mu 74-202, 7 males, 3 females (sl 2.3-7.8 mm).
ZMUC collections: Mortensen's 1914 Expedition, S'05.3' S, 150°04'E, 12.9.14, 200-260 m, 1 ovigerous female sl = 10.4 mm).
DESCRIPTION: Shield (Fig. 37b) usually longer than broad. Rostrum triangular, often reaching beyond level of lateral projections, acute, usually with terminal denticle. Ocular peduncles stout, short, 0.500.65 shield length, dorsomesial surface with row of stiff setae; corneas not dilated, maximum width included 2.5-3 times in peduncular length. Ocular acicles roundly triangular, with distal half of dorsal surface corneous or only weakly calcified, usually with small marginal, terminal denticle; frequently approximate in distal half. Antennular peduncles over-reaching ocular peduncles by slightly less to more than entire length of ultimate segment. Antennal peduncles exceeding distal margins of corneas by 0.50-0.65 length of ultimate segment, but reaching only to distal half of ultimate segment of antennular peduncle; second segment with laterodistal projection strongly produced into broad, triangular process, terminating in acute simple or rarely bifid tooth, mesial margin unarmed or with distal tooth, lateral margin with 1 or 2 often widely separated teeth or denticles. Antennal acicle usually reaching at least to middle of ultimate peduncular segment, stout, slightly arcuate, with row of tufts of stiff setae on mesial margin and terminating in small tooth.
Right cheliped (Fig. 38b) massive, operculate. Dactyl broad, slightly shorter to slightly longer than palm; dorsal surface slightly elevated in the midline proximally, smooth, slightly pitted, or with scattered low tubercles, granules or short transverse ridges, dorsomesial margin faintly or weakly crenulated and with 1 blunt tubercle proximally, mesial and ventral surfaces with very low, flattened, frequently corneouscapped, blister-like tubercles. Palm with maximum breadth usually greater than length, dorsomesial distal angle armed with prominent simple or multifid tooth; dorsomesial margin usually with irregular row of 4-6 (rarely 2 or 3) acute or blunt, tuberculate teeth, occasionally only row of small, spinose teeth; dorsal surface convex, smooth, faintly pitted, or covered with flattened granules and small tubercles, often with 1 or 2 prominent tubercles at proximal margin; dorsolateral margin not delimited, usually unarmed; mesial and lateral faces with scattered low tubercles or granules; ventral surface usually with several large, flattened, blister-like tubercles, often with corneous surfaces. Carpus subquadrate when viewed dorsally; dorsomesial distal angle depressed and with small tooth, dorsomesial surface with 1 very strong, usually blunt tooth distally and frequently single or double row of much smaller teeth or tubercles proximally, dorsal surface with scattered, low, blunt or spinulose tubercles in mesial half, very short, transverse ridges in lateral half, distal margin with few to several blunt teeth; dorsolateral margin not delimited, lateral and mesial surfaces with scattered blunt or spinulose tubercles or granules, ventral surface with scattered low tubercles or granules, strongest in lateral half. Dorsomesial margin of merus unarmed or occasionally with 1 or 2 small teeth distally; ventrolateral margin with 1 or 2 strong acute spines at distal angle and few smaller teeth or tubercles proximally; ventromesial margin unarmed or with 1 or 2 smaller spines at distal angle; ventral surface with scattered granules or tubercles, 2 or 3 moderately large tubercles on somewhat produced lateral protuberance.
Left cheliped (Fig. 38d) not reaching to base of dactyl of right, slender; rotation of propodal carpal articulation approximately 45° from perpendicular. Dactyl with surfaces unarmed but with scattered tufts of short setae. Palm with 1-3 low protuberances on tubercles on dorsomesial margin; surfaces all unarmed, but with few scattered setae, particularly on fixed finger. Carpus with 1 strong, acute or blunt tooth on dorsomesial margin distally, and row of 3-5 small, blunt or subacute teeth or tubercles proximally; dorsolateral margin not delimited. Merus with unarmed dorsal margin; ventrolateral margin unarmed or with row of very small acute, simple or bifid denticles, ventral surface sometimes with 1 or 2 very small denticles and usually 1 moderately prominent tubercle proximally near mesial margin.
Ambulatory legs (Fig. 37d) similar. Dactyls 1.35 times to nearly twice length of propodi; in dorsal view, straight or very faintly twisted in distal third; dorsal margins each with row of tufts of long, stiff setae; mesial faces often somewhat concave, each with 2 or 3 sparse rows of tufts of short to moderately long setae, or short, stiff and spiniform bristles; lateral faces with few tufts of short setae; ventral margins each with row of 12-31 spiniform setae (number increasing with increased animal size). Propodi with few scattered setae on dorsal surfaces; ventrodistal angles each with 1 or 2 small spiniform setae, ventral surfaces frequently with row of widely spaced, small spiniform setae, at least on second. Carpi each with small tooth at dorsodistal angle, dorsal surface with sparse row of setae. Meri with scattered setae on dorsal an:: ventral margins. Fourth pereopods with propoda: rasp consisting of 1 long row and 1 or rarely 2 ver. short to moderately long rows of scale-like setae Anterior lobe of sternite of third pereopods subrectangular, with central fringe of short setae. Sternite of fifth pereopods broadly rectangular, with 2 prominent tufts of setae.
Telson (Fig. 37f) with posterior lobes asymmetrical, left largest, separated by moderate median cleft, terminal margins each with row of very small denticles.
COLOUR: "Eyestalks, antennules, antennae, chelipeds. and walking legs a uniform light orange-brown ('apricot') colour" (Schembri & McLay 1983).
VARIATIONS: As is apparent from the description, B. yaldwyni exhibits considerable variability, particularly in chela morphology. In contrast to many pagurids where the strength of chela armature decreases with increasing animal size, tubercles and spines in B. yaldwyni increase in strength and number in large specimens of both sexes. Similarly, the number of spiniform setae on the ventral margins of the pereopodal dactyls increases from 12 to 18 in animals with shield lengths of < 3 to 6 mm to 25-31 in animals with shield length over 9.5 mm.
REPRODUCTION: Twenty of the 41 females examined were carrying eggs; the smallest had a shield length of 5.0 mm, the largest 12.4 mm. On each of the anterior three pleopods, these females usually carried a cluster of 20-30 relatively large eggs, with diameters varying from 1.2 to 1.6 mm. The majority of ovigerous females were collected in January, May, and September.
HABITAT: A variety of gastropod shells in the Otago region (Schembri & McLay 1983), but most commonly Fusitriton sp. and less frequently Iredalina sp. in the material examined.
REMARKS: Characters differentiating B. yaldwyni from B. cruentus were detailed under the latter species. McLaughlin (1994) noted that one specimen of B. yaldwyni (sl = 9.6 mm) parasitised by an unidentified rhizocephalan had female-appearing pleopods, but neither male nor female gonopores were present. A slightly smaller male specimen (sl = 8.0 mm) examined more recently showed a similar pleopod condition.
RECORDS FROM NEW ZEALAND: Eastern North Island and from North Cape to north of Mayor Island, and western South Island from Westport to the Solander Trough including area off Otago Heads, and northern Campbell Plateau; 256-695 m.
DISTRIBUTION: New Zealand; southeastern Australia; Tasmania.”
(Saint, Laurent et al, 2000: 120-123)
