Pseudoleptochelia juliae Morales-Núñez, Heard & Alfaro, 2013, n. sp.

Pseudoleptochelia juliae n. sp.

Figs. 2–7, 8 B, 9–12

Synonyms. Pseudoleptochelia sp. A: Heard et al. (2004), p 112, fig. 151; Suárez-Morales, et al. (2004), pp. 72–76, figs 36–39; and García-Madrigal et al. (2005), p 1173.

Material examined. Pseudoleptochelia juliae Holotype. Adult male, length 2.2 mm, (USMN 1204767), 17° 56’47.41’’N, 67° 04’56’’W, North San Cristóbal Southwest of La Parguera, Puerto Rico, depth 12.2 m, collected with benthic grab in June 18 of 2008. Paratypes (same collection data as for holotype): two males (USMN 1204768), seven females (USMN 1204769); two males and two females (GCRL 6510). Additional specimens from the type locality are in the collection of authors.

Pseudoleptochelia anomala three males, twelve females, Balearic Islands, Spain

Diagnosis. Female : Antenna with article-3 having anteriodorsal margin with simple seta only. Maxilliped having inner margin of each endite with two rounded denticles. Carapace with transverse suture indicating second thoracomere. Chela inner comb with two to three stout setulate surrounded by minute setae. Pereopods 4 to 6 posterodistal margin with pair of short, stout pectinate, spiniform seta. Male: Antennule with flagellum article-1 appearing composite with 5–6 bundles of aesthetascs, 10–12 partially fused or unfused articles each with distoventral tuff of aesthetascs, distal article minute with four long simple setae. Antenna with dorsal margins of articles 2 to 4 each with long, anteriorly curved, simple seta; ventral margins of articles 2 to 3 lacking simple setae; distoventral margin of article-4 with long simple seta. Cheliped subchelate, appearing carpochelate, carpus with well-developed sub-acute inferior process; propodus length more than twice width, fixed finger reduced to short distal process with strong spine on inner margin. Uropod in both sexes with endopod usually having four articles or incipient articles.

Etymology. This species is named in honour of Julia Stella Núñez, the mother of the senior author.

Type locality. Off North San Cristóbal southwest of La Parguera, Puerto Rico, depth 12.2 m, soft substrata (sand).

Distribution. Puerto Rico; possibly southern Florida, eastern Gulf of Mexico, and Mexican Caribbean.

Description. Adult Female.

Body (Figs. 2 A–B; 11): Length 2.6 to 3.2 mm, about 7.5 times width.

Carapace (Figs. 2 A–B; 9A–B): About 18 % of total body length, slightly longer than pereonites 1–2 combined; distinct transverse dorsal suture on posterior third with finer line extending anterolaterally to each ventral edge (apparently indicating demarcation of second thoracomere); mid-dorsal divided-plate structure between dorsal suture and dorsal margin of first pereonite. Eye lobes sub-acute with fine suture separating them from carapace (Figs. 2 B −9B). Eyes dark pigmented having 8–10 ommatidia. Four to six simple setae laterally behind eye lobes (Figs. 2 A–B; 9A–B).

Pereonites (Fig. 2 A): About 60 % of total body length; pereonites 1–3 and pereonite-6 wider than long, pereonite 4−5 longer than wide.

Pleonites (Fig. 2 A): About 16 to 18 % of total body length, pleonites 1–5 sub-equal in length, much wider than long; pleonite-1 with pair of small simple, sub-marginal setae dorsally; lateral margins of pleonites 2–5 each with mid-marginal seta (Fig. 2 A).

Pleotelson (Fig. 2 A): About 5% of total body length, sub-equal in length to pleonites 4–5 combined, posterior margin with two pairs of medial terminal simple setae, innermost pair relatively long reaching nearly past basal article of uropod.

Antennule (Figs. 3 A; 9A–C, 9E): Relatively short and broad from dorsal and ventral aspect, about one seventh of total body length, with three articles plus terminal article. Article-1 length more than twice that of articles 2–3 combined, dorsal and ventral seta on mid-margin, four sensory setae on mid-ventral margin, simple seta and two sensory setae on sub-distal ventral margin. Article-2 slightly longer than wide, with one dorsal and one ventral simple setae, and sensory seta on dorsodistal margin. Article-3 length about 2.3 times width, with simple seta on dorsodistal margin. Terminal article minute, with five simple setae, one broom seta, and aesthetasc.

Antenna (Figs. 3 B; 9F): Article-1 reduced, asetose; article-2 slightly longer than wide, with two small simple setae on each distal margin; article-3 quadrate, with simple seta on distodorsal margin. Article-4 with length slightly less than combined lengths of article 2–3, about three times width, with two short and two long simple setae on sub-distal margin. Article-5 with length slightly more than half that of article 4, about 2.5 times width, two long simple setae on sub-distal margin. Article-6 minute, with two short and two long, simple setae.

Mouthparts: Labrum (Fig. 3 C): As illustrated.

Mandible (Figs. 3 D–E): Left: lacinia mobilis, broad, sub-triangular with three to four shallow, sub-distal denticles (Fig. 3 D), incisor with one small proximal and two weak shallow distal lobes. Right: incisor weakly bidentate distally, with six denticles on upper margin, (Fig. 3 E). Molar process stout, with grinding surface having fine denticulation.

Labium (Fig. 3 F): Bilobed, lobes equal and wide, finely setose distally. Maxillule (Fig. 3 G): Endite having 9–10 relatively slender distal spines, sub-distal and outer margin setose. Palp slender with two long terminal setae of unequal length.

Maxilla (Fig. 3 H): Sub-quadrate.

Maxilliped (Figs. 4 A–B): Bases distally unfused, distal margin usually with four, occasionally five, pairs of long simple setae, extending to palp article-2. Endites not fused, each having finely setose lateral margins with relatively long inwardly curved lateral seta, distomedial margin with two stout tooth-like spines, and inner distal margin with stout distally rounded denticle with minutely papillate (under high magnification) surface (Fig. 4 B), inner medial margin with two pairs of small narrow coupling hooks. Palp: Article-1 asetose. Article-2 with short simple seta on outer margin and cluster of three simple setae on sub-distal inner margin. Article-3 with five simple setae (proximal three strongly developed) on inner margin. Article-4 with seven distal simple setae, and simple seta sub-distally.

Epignath (4C): Elongate, strap-like, with margins finely setose.

Cheliped (Figs. 4 D −E; 9B–D): Coxal sclerite sub-triangular, dorsally inserted with respect to basis, having two simple setae (Figs. 4 D; 9D). Basis elongate, length about 2.5 times width; simple seta on sub-distal lateral margin. Merus triangular, having posterior margin with two closely-approximated rows (one with five and other with three) of long simple setae. Carpus length about 1.8 times width, with anterior margin having six small spiniform setae and simple setae distally; three long simple setae on mid-posterior margin; distal margin extending to form cuff partially covering propodus. Propodus length about twice width, simple seta on anterodistal margin just below dactylus, fixed finger with anterior margin having three simple setae on outer incisive margin and two on midposterior margin; Inner aspect (Figs. 4 E; 10A): with oblique dense row of minute setae and two to three small, stout setulate setae just proximal to articulation with dactylus. Dactylus (movable finger) longer than fixed finger, inner face with setulate seta proximally.

Pereopod-1 (Fig. 5 A): Distinctly longer than other pereopods. Coxa with simple seta on anterodistal margin. Basis slender, length about 3.3 times width, and length about equal to that of ischium, merus and carpus combined; anteroproximal margin with simple seta. Ischium reduced, with simple seta. Merus appearing asetose, length about half that of basis. Carpus length about equal to that of merus, with five distal and sub-distal setae. Propodus length about 3.6 times width, slightly longer than carpus; four sub-distal simple setae, three (one minute) on or near anterior margin, and one on posterior margin. Dactylus narrow, styliform, naked; together with unguis longer than propodus. Unguis longer than the dactylus

Pereopod-2 (Figs. 5 B; 2B): Coxa with simple seta on anterodistal margin (Fig. 2 B). Basis length about equal to that of ischium, merus, and propodus combined; proximal third of anterior margin with simple seta and two sensory setae. Ischium with two setae (one minute), on anterior margin. Merus appearing asetose, length about one third that of basis. Carpus length about equal to that of merus; antero- and posterodistal margins each with simple seta. Propodus length slightly more than 1.3 times that of carpus with two relatively-long simple setae (longest about equal in length to that body of propodus), posterodistal margin with minute spiniform seta. Dactylus and unguis length together slightly more than half that of propodus; dactylus with simple accessory seta (not shown) originating just proximal to junction of dactylus and unguis. Unguis with pore at tip for extrusion of tube-building material.

Pereopod-3 (Fig. 5 C): Similar to pereopod-2, but smaller. Basis slightly less than 40% total length of pereopod, antero-proximal margin with simple seta and sensory seta. Reduced ischium with simple seta on anterior margin. Merus length slightly more one third that of basis; minute spiniform seta on posterodistal margin. Carpus, propodus, and dactylus as in pereopod-2.

Pereopod-4 (Figs. 5 D; G–J; 10B): Basis, length about 1.4 times that of ischium, merus, and carpus combined; cluster of small sensory setae on mid-anterior margin and two sensory setae on posterior margin. Ischium about three times as wide as long, with mid-posterior simple setae. Merus, length about 1.4 times width, with distal posterior margin bearing two setae attenuated distally into styliform tips (Fig. 5 G). Carpus, length about 1.3 times width, articulated obliquely with merus, anterodistal margin with small simple seta; posterodistal margin with three stout (as wide as long or wider), tooth-like dissimilar setae (Figs. 5 H–I). Propodus, narrower and slightly longer than carpus; anterodistal margin with three subequal finely pectinate setae (longest about equal in length to dactylus); posterodistal margin (immediately adjacent to articulation with dactylus) with pair of short, stout pectinate, spiniform seta (Figs. 5 J; 10B). Dactylus articulated posterodistally with propodus; small simple seta just proximal to unguis; unguis minute, with dactylus forming claw-like tip.

Pereopod-5 (Figs. 5 E; 10C): Similar to pereopod-4, except basis appearing asetose. Ischium with two simple setae on posterior margin.

Pereopod-6 (Figs. 5 F, 10D): Similar to pereopods 4–5, except ischium with single simple seta; propodus with anterodistal margin having two sub-equal long finely pectinate and three curved, “comb-like” setulate setae.

Pleopods (Fig. 5 K): Five similar, well-developed, biramous pairs. Basal article broad, with inner plumose seta. Rami with lengths slightly more than twice widths, both with proximally inflated plumose seta on distal inner margin adjacent to articulation with basis. Endopod with inner and distal margins bearing 10 long plumose setae, distal-most seta modified (greatly attenuated, filament-like distally); with strongly developed plumose seta on midlateral margin. Exopod with inner and distal margins bearing 14 long plumose setae, lateral margin asetose.

Uropod (Fig. 5 L): Basal article about as long as wide, asetose. Exopod uniarticulate, extending past midpoint of article-2 of endopod, with simple seta on outer mid-margin, two distal simple setae (outer seta longest, about equal combined lengths of basis and exopod; inner seta about one third length of outer). Endopod usually with four or five incipient articles; article-1 almost half length of exopod, with inner distal simple setae. Article-2 length about twice width, inner distal margin with sensory seta. Article-3 nearly as long as exopod with simple seta and sensory setae near inner distal margin. Article-4 almost same length as article-3 with simple seta on mid-margin with sensory seta and five (three long, two small) simple setae and on inner distal margin.

Male. Body (Figs. 6 A, 12A): Natatory, smaller than female. Length about 2.0 to 2.3 mm.

Cephalothorax (Fig. 6 A): Length of carapace nearly equal to that of pereonites 1 to 3 combined, rostrum weak; ocular lobes bearing large eyes with visual elements present, eyes about 5 times larger than in female, about 25 % of total carapace length.

Pereonites (Fig. 6 A): About 50% of total body length. Pereonites 1 to 4 becoming progressively longer; pereonite-5 same length that as pereonite-4; pereonite-6 same length as pereonite-3; pereonites 1 to 3 wider than long; pereonites 4 to 5 same length, and quadrate.

Pleonites (Fig. 6 A): About 20% of total body length, combined length about equal to that of combined length of pereonites 5–6; all pleonites sub-rectangular, wider than long; pleonite-1 with one small simple seta on midlateral margin; pleonites 2–5 with two small simple setae on mid-lateral margin.

Pleotelson (Fig. 6 A): About 5% of total body length with rounded margin, length slightly less than combined length of pleonites 4–5; posterior margin with two pairs of simple setae, inner-most pair relatively long extending well-past uropodal basal article.

Antennule (Figs. 6 A–C): Peduncle with three articles. Article-1, length about 1.7 times width with disto-dorsal simple setae. Article-2, length about 1.6 times width, with disto-ventral rounded apophysis. Article-3 saddle-shape forming dorsal shelf over first apparent flagellar article, with small simple seta dorsally and laterally (Fig. 6 C). Flagellum having ventral margin with 15–16 aesthetasc bundles and 10–13 articles. Article-1 with four to five bundles or short rows of aesthetascs. Article-2 often partially fused with composite article 1. Articles from article- 2 to penultimate article (10 or 11) each with disto-ventral bundle of aesthetascs. Terminal article minute with simple setae (Fig. 6 B).

Antenna (Fig. 6 D): With six articles. Article-1 compressed, asetose. Article-2 wider than long, with sensory seta ventrally on sub-distal margin; long simple seta dorsally on distal margin. Article-3, smaller than article-2, wider than long, ventral margin with sensory seta sub-distally; dorsal margin with long simple seta distally. Article- 4 length about 3.7 times width, longer than combined length of articles 2 to 3, dorsal margin with long simple setae medially; ventral margin with sensory seta medially and long sub-distal seta. Article-5 length about 6.5 times width, slightly longer than article-4, with four simple setae distally. Article-6 minute, with three long terminal setae.

Mouthparts: Unrecognizable, atrophied mass.

Maxilliped (Fig. 6 E): Atrophied, area of basis with four simple setae; palps greatly reduced with two recognizable, partially fused articles.

Cheliped: Inner aspect (Fig. 7 A–B): Subchelate and appearing carpochelate. Basis length about twice width. Merus triangular with posterior margin having three distal and one proximal simple setae. Carpus with anterior margin having six small spines and simple seta distally; posterior margin with disto-ventral apophysis bearing three simple setae. Propodus length about 2.6 times width; fixed finger reduced to small pointed apophysis with small tooth on inner proximal margin, with five inner (2 anterior and 3 posterior) simple setae; inner palm of propodus with comb row of 13 setae (11 short and two longer setae near base of dactylus). Dactylus slender, equal in length to propodus, with one simple seta near to anteroproximal margin; posterior margin with row of fine setae along cutting edge.

Pereopod-1 (Fig. 7 D): Similar to that of female, except for minor differences in setation and proportionately longer carpus and propodus. Dactylus, long falciform; including unguis, slightly shorter than propodus; unguis slightly longer than dactylus.

Pereopod-2 (Fig. 7 E): Appearing more elongate than in female, not noticeably modified for tube construction. Coxa with simple seta on anterodistal margin. Basis similar to that of female with length nearly 3.0 times width, simple seta on anterior proximal margin. Ischium reduced with two minute setae on posterior margin. Merus length about one third that of basis; small, stout, spiniform seta on posterodistal margin. Carpus length about 1.8 times that of merus; anterodistal margin with well-developed, narrow, acute spiniform seta; posterodistal margin with two spiniform setae. Propodus length slightly more than 1.2 times that of carpus, anterior margin with sub-distal seta; posterodistal margin with pair of narrow spiniform setae. Dactylus and unguis together weakly curved posteriorly, length slightly more than 40% that of propodus; unguis, about one third length of dactylus. Unguis appearing to lack distal opening.

Pereopod-3 (not figured): Similar to pereopod-2.

Pereopod-4 (Figs. 7 F and 7H): Basis, length about 2.8 times width. Ischium reduced, appearing asetose. Merus, length about 2.4 times width, with distal posterior margin bearing two well-developed, narrow, spiniform setae (not proximally inflated as in female). Carpus length slightly longer than merus, anterodistal and sub-distal margins with small sub-distal simple seta and three spiniform setae (Fig. 7 H). Propodus length about two thirds that of basis; distal margin with three setae and sub-distal spiniform seta. Dactylus and unguis, narrow, length about 70% that of propodus, weakly curved posteriorly with minute setae on posterior concave margin; unguis about on third length of dactylus.

Pereopod-5 (not figured): Similar to pereopod-4.

Pereopod-6 (Fig. 7 G): Similar to pereopods 4–5, except for basis slightly longer; propodus shorter with superior distal margin with five, two long finely pectinate and three curved setulate “comb-like” setae.

Pleopod (not figured): Five pairs, similar to, but more strongly developed than those of female with longer plumose setae.

Uropod (Fig. 7 I): Similar to the female, but exopod being a little more setose.

Remarks. As redefined here, we currently recognize seven nominal species of Pseudoleptochelia: P. anomala, P. fairgo, P. magna, P. mortenseni, P. straddi, P. juliae n. sp., and the recently described Pseudoleptochelia occiporta. As mentioned previously, P. occiporta which has affinities with P. fairgo, be will treated by R. Bamber in the near future, and it has not been included in the key presented here. An apparently undescribed species of Pseudoleptochelia from the northern Pacific coast of Costa Rica was reported by Heard et al. (2009); but no males are known for this species. The males and females of “ Pseudoleptochelia sp. A” (sensu Heard et al. 2004; Suárez- Morales et al. 2004; and García-Madrigal et al. 2005) are very similar to those of P. juliae. Although there are some slight morphological variation exhibited by these more northern and western populations, we tentatively consider them as conspecific with the specimens of the new Puerto Rican species. The nominal species of Pseudoleptochelia, excluding P. occiporta, can be separated in the following key.

Key to the recognized males of Pseudoleptochelia based on the cheliped.

1. Cheliped with ventral carpal apophysis or process (appearing carpochelate)....................................... 5

- Cheliped lacking ventral carpal apophysis or process......................................................... 2

2. Cheliped with propodus having mid-ventral rounded apophysis just distal to setal comb row (Fig. 8 E) … P. straddi [Australia]

- Cheliped with propodus lacking mid-ventral rounded apophysis................................................ 3

3. Cheliped having propodus with 17 setae in comb row; fixed finger without distinct sub-distal tooth (Fig. 8 I)............................................................................................. P. m a g n a [Mediterranean]

- Cheliped having propodus with 14 or less setae in comb row................................................... 4

4. Cheliped having propodus with 11 anterior setae in oblique, sub-distal, comb row; fixed-finger with distinct sub-distal tooth or tubercle (Fig. 8 A).................................................. P. m o r te n s e n i [Southern Caribbean: Tobago]

- Cheliped having propodus with about 14 setae in sub-linear comb row (Fig. 8 J); fixed finger without distinct sub-distal tooth (Fig. 8 K)...................................................................... P. anomala [Mediterranean]

5. Cheliped having the ventral carpal processes and the ventral propodal processes blunt and rounded (Fig. 8 D); propodus relatively robust, length less than twice width.................................................. P. fairgo [Australia]

- Cheliped having the ventral carpal processes and ventral propodal processes sub-acute to acute (Fig. 8 B). Propodus relatively narrow, length distinctly more than twice width................ P. juliae [Caribbean, Gulf of Mexico, Florida East coast].

The male of P. juliae is distinguished from that of P. mortenseni, the only other nominal member of the genus known from the NW Atlantic, by the latter having chela with a only a shallow, raised bump on the carpus, with three associated simple setae (Fig. 7 A, 8A, respectively). The chelae of the two species also differ in the number and form of the comb setae on the inner sub-distal face of the propodus; there are 13 setae becoming gradually longer posteriorly (ventrally) on P. juliae (Fig. 7 A), whereas on P. mortenseni the setal row is irregular with 11 setae (Fig. 8 A); the first seta is longer than all but the last two, which are subequal and distinctly longer than all the rest (Fig. 8 A). Further, the male antennule of P. juliae has ten aesthetasc-bearing articles whereas that of P. mortenseni has seven. The stout female antennule attributed to small females/ neuters of P. mortenseni by Lang (1973: fig. 16g) is quite similar to those of P. juliae (see Remarks for the genus). Until their mouthparts can be carefully compared, we are unable to reliably separate the females of these two Caribbean species.

Another form of a Pseudoleptochelia male (form A) co-occurs in Puerto Rican waters with the males and females attributed to P. juliae. Though similar (see Figs. 6 F; 12B) in many aspects to the male holotype of P. juliae, there are some distinct differences. “ Male form A ” is briefly diagnosed as follows:

Male form A : Antennule (Fig. 6 F) with flagellum having nine aesthetasc-bearing articles. Cheliped; lateral aspect (Fig. 6 F) carpus with anterior margin having six small spiniform setae and simple setae distally; with distinct narrow process on posterior margin; inner aspect (Fig. 7 C) with propodus having sub-distal, oblique combrow of 13 to 14 stout setae gradually increasing in length anteriorly [eleven short and two long setae in juliae]; fixed finger of propodus with proximal tooth adjacent to articulation with dactylus. Dactylus weakly falcate, subequal in length to propodus with proximal simple seta on upper inner margin, three minute setae on inner concave margin.

There is a possibility that P. j u l i a e and the ‘ Pseudoleptochelia male Form A’ may represent two sympatric, cryptic species for which their respective females appear to be indistinguishable. This may also be the case for P. fairgo and P. straddi (see Bamber 2008).

With respect to non-Caribbean species, the male and female of P. juliae appear to be most similar to those of the Australian P. fairgo (see Bamber 2005, 2008). This species has recently been transferred to the genus Parakonarus by Edgar (2012); however, for the reasons given previously under the Remarks for the genus we retain it within Pseudoleptochelia. The males for both P. juliae and P. fairgo have a prominent carpal process making them appear carpochelate (Figs. 8 B and 8D). In the male of P. anomalus, a distinctive carpal process is not developed, although possibly represented by a raised ridge bearing a few simple setae (Fig. 8 K). In the subchelate male of Parakonarus sensu Bird 2011 (Fig. 8 L), there is a much less prominent blunt process with simple setae.

The male of Pseudoleptochelia juliae can be distinguished from that of P. fairgo by the cheliped having the propodus distinctly narrower (length more than twice width) and the carpus having a sub-acute carpal process or apophysis. The females are separated by P. juliae having (1) more “spatulate spines” on the distal medial inner margins of the maxillipedal endites, (2) a greater number of setae on the carpus of the cheliped (eight versus five), (3) apparently fewer articles or incipient articles in the uropodal endopod (four versus five), and (4) pereopods 4–6 posterodistal margin with pair of short, stout pectinate, spiniform seta.

The females of P. juliae and P. f a i rg o, as well as those of the genera Konarus and Parakonarus are characterized by having (1) the maxillipedal basis with four or five sub-distal pairs of long simple setae (see Fig. 4 A); and (2) the merus of pereopods 4–6 having a pair of distinctive proximally swollen and distally attenuated (styliform) setae (appearing setulate) and a carpus with stout spiniform setae (as wide or wider than long) on the distal margin (Figs. 5 G; 5H −I, respectively). The antennae of P. anomala, P. juliae, P. fairgo and members of genera Konarus and Parakonarus also lack distinctive buttressed thorn setae on the distal margins of their second and third antennal articles. This may, at least superficially, link these two genera, and possibly the other members of “ anomala group,” to the subfamily Heterotanaidinae sensu Larsen & Wilson, 2002. In a more recent cladistical treatment of the superfamily Paratanaoidea, Bird & Larsen (2009) the two leptocheliid subfamilies were not resolved separately but a more refined approach may do this.

Based on our observations on the male of P. juliae and the descriptions and illustrations of Bird (2011) for the males of Parakonarus kopure and P. robertsoni, we believe that the first “apparent” article of the antennular flagellum represents a composite of three to six precursor proximal articles. The first “apparent” article in the antennular flagellum of P. j u l i a e, P. mortenseni, and P. kopure, have five to six, four, and three clusters of aesthetascs, respectively. This condition has not been reported for the males of P. f a i rg o and P. straddi nor in the earlier descriptions or illustrations for the males of P. anomala (see Sars 1886, Smith 1906, Riggio 1996) and P. magna (see Smith 1906); however, based on examination of the males we attribute to P. anomala, three clusters of aesthetascs are present on the first apparent flagellum article. The significance of this apparent fusion and compression of the first few proximal flagella articles for males within the Pseudoleptochelia complex remains to be determined.

Habitat: Pseudoleptochelia juliae occurred on soft bottom sites off La Parguera and Culebra Island in depths ranging from 1 to 28 m. Other tanaidaceans co-occurring with it included: Mesokalliapseudes quadriflagellata Drumm & Morales-Núñez, 2012, Leptochelia spp., Pseudotanais sp., and Swireapseudes sp.