Pylopaguridium markhami McLaughlin & Lemaitre, 2001

Lemaitre, Rafael, 2020, New and rare micro-pagurid hermit crabs (Crustacea: Anomura: Paguridae) from the Caribbean Sea and Gulf of Mexico, Zootaxa 4722 (4), pp. 301-325 : 320-323

Pylopaguridium markhami McLaughlin & Lemaitre, 2001

( Figs. 11C, D , 15–17 )

Pylopaguridium markhami McLaughlin & Lemaitre, 2001: 472 , figs 14c, d, 15, 16; Lemaitre & McLaughlin, 2003: 467; McLaughlin et al. 2010: 35.

Material examined. Bocas del Toro Province, Panama, Caribbean Sea : 1 male 1.6 mm, Punta Puebla, 9.367°N, 82.291°W, BBDT-0608, BCS2016–012, 4–4.5 m, lagoon fringing reef, Agaricia reef framework, 16 May 2016, colls M. Leray, F. Michonneau, R . Lasley ( UF 044314); 1 female 1.0 mm, 1 imm sex indet 0.9 mm, runway, 9.342°N, 82.260°W, BBDT-2089, BCS2016–034, 4–4.5 m, lagoon fringing reef, Agaricia reef framework, 23 May 2016, colls M. Leray, F. Michonneau, R . Lasley ( UF 044399); 1 male 1.4 mm, same station data as previous, BBDT- 1279, BCS2016–023 ( UF 044396); 8 males 1.3–2.2 mm, 3 females 1.6–2.1 mm, 3 ov females 1.4–2.1 mm, Seagal, 9.289°N, 82.296°W, BBDT-2888, BCS2016–043, 3–3.5 m, lagoon fringing reef, Agaricia reef framework, 27 May 2016, colls M. Leray, F. Michonneau, R . Lasley ( UF 044528) .

Recognition characters. Shield ( Fig. 15A ) slightly to distinctly longer than broad; lateral projections prominent, acutely subtriangular, reaching beyond level of tip of rostrum, terminating in sharp marginal or submarginal spine. Rostrum obtusely subtriangular, terminating in sharp spine. Ocular peduncles moderately long and slender, approximately 0.8 as long as shield, each with median bristle-like seta on mesial surface; corneas weakly dilated. Ocular acicles multifid, each terminating in 4 or 5 slender spines. Antennular and antennal peduncles reaching to distal margin of corneas; antennal acicles curving outwards, terminating in strong spine, with few setae mesially. Chelipeds nearly similar in length but distinctly dissimilar in strength and spination; right ( Fig. 16A, B ) approxi- mately twice as wide as left, sparsely setose, chela with numerous blunt spines or tubercles on dorsal surface, carpus with dorsolateral and dorsomesial row of spines; left ( Fig. 16C, D ) sparsely setose, chela with scattered small tubercles on dorsal surface, carpus with dorsal row of well-spaced spines. Pereopods 2 and 3 ( Fig. 17 A–D) similar from left to right; sparsely setose, lacking spines except for ventromesial row of 7 or 8 corneous spinules increasing in size distally on each dactyl. Pereopod 4 ( Fig. 16E ) lacking preungual process on dactyl; propodal rasp ( Fig. 17E ) with 1 row of ovate scales. Anterior lobe of sternite XI (of pereopods 3; Fig. 15B ) rounded, armed with 1 or 2 small spines anteriorly. Uropods strongly asymmetrical, left largest. Telson ( Fig. 15C ) nearly symmetrical, longer than broad, with distinct lateral indentations; posterior lobes separated by deep U-shaped median cleft, posterior margins nearly straight or slightly oblique, each armed with 3 or 4 spines.

Color ( Fig. 11C, D ). Shield mostly cream-white with somewhat darker portions laterally, and light brown region one each side of anterior half. Ocular peduncles cream-white dorsally, faded purple ventrally; cornea white with reddish spots. Antennular peduncles blue; upper flagella reddish ventral portion. Antennal peduncles cream-white in background, with second segment having brownish portions laterally and mesially, acicle with distal brownish band; flagella dark brown with approximately 8 short white bands. Right chela with dactyl and fixed finger white with brownish teeth, palm with faded to brownish spines over whitish background. Left cheliped white, palm with dark brown region distomedially and distomesially; carpus and merus brown with lateral and mesial faces mostly brown. Pereopods 2 and 3 (ambulatory legs) white with short dark brown stripes as follows; 1 dorsomedially on basal portion of dactyl, and 3 medially on dorsal, lateral and mesial faces of merus, carpus and propodus.

Distribution. Caribbean Sea, from the Turk and Caicos Islands in the Bahamas, off eastern Honduras, and now Bocas del Toro, Panama. Depth: 3– 36 m.

Remarks. This species is included in the “ Pylopagurus-Tomopagurus ” group, and prior to this study, was known exclusively from the specimens used in the original description by McLaughlin & Lemaitre (2001) from the Bahamas and off eastern Honduras. Subsequently, this species was listed in a taxonomic summary of the “ Pylopagurus-Tomopagurus ” group of genera and species ( Lemaitre & McLaughlin 2003), and in a checklist of the Paguroidea of the world ( McLaughlin et al. 2010). The presence of Pylopaguridium markhami in Bocas del Toro, Panama, in the southwestern Caribbean Sea, amplifies even more its distribution in the West Indian region.

The original description of Pylopaguridium markhami included partial and somewhat unfocused photographs of the dorsal aspect of the left and right cheliped of a female, illustrations of various body parts of a male, and sternite XIII and first gonopods of a female ( McLaughlin & Lemaitre 2001: figs. 14c, d, 15). Herein are included illustrations of a female (shield length = 2.1 mm, UF 044528) from Bocas del Toro, Panama, showing all diagnostic aspects with more complete details and views.

Figures

FIGURE 11. A, Paguriscus robustus Lemaitre, Felder & Poupin, 2017, Bocas del Toro Province, Panama, Caribbean Sea: male, 1.2 mm (UF 044397); B, Nematopaguroides karukera Lemaitre, Felder & Poupin, 2017, Bocas del Toro Province, Panama, Caribbean Sea: ov female in shel 1.8 mm (UF 044300); C, D, Pylopaguridium markhami McLaughlin & Lemaitre, 2001, Bocas del Toro Province, Panama, Caribbean Sea: C, male 1.6 mm (UF 044314); D, male 1.4 mm (UF 044396). Scales: 1.0 mm (A), 2.0 mm (B–D). (Photographs: G. Paulay)

FIGURE 15. Pylopaguridium markhami McLaughlin & Lemaitre, 2001, female 2.1 mm, Seagal, Bocas del Toro Province, Panama, Caribbean Sea (UF 044528): A, shield and cephalic appendages, dorsal; B, sternum and coxae of pereopods 1–5, ventral; C, telson, dorsal. Scale: 0.5 mm.

FIGURE 16. Pylopaguridium markhami McLaughlin & Lemaitre, 2001, female 2.1 mm, Seagal, Bocas del Toro Province, Panama, Caribbean Sea (UF 044528): A, right cheliped, dorsal; B, same, lateral; C, left cheliped, dorsal; D, same lateral. Scale: 0.5 mm.

FIGURE 17. Pylopaguridium markhami McLaughlin & Lemaitre, 2001, female 2.1 mm, Seagal, Bocas del Toro Province, Panama, Caribbean Sea (UF 044528): A, left pereopod 2, lateral; B, dactyl of same, mesial; C, left pereopod 3, lateral; D, dactyl of same, mesial; E, propodus and dactyl of left pereopod 4, lateral. Scale: 0.5 mm.