Paguristes turkayi, Ayón-Parente & Hendrickx & Cáceres, 2022

Ayón-Parente, Manuel, Hendrickx, Michel E. & Cáceres, Ignacio, 2022, Redescription of Paguristes aztatlanensis Glassell, 1937 and description of a new species of the genus Paguristes Dana, 1851 (Anomura, Paguroidea, Diogenidae) from western Mexico, Zootaxa 5128 (2), pp. 269-283 : 275-282

Paguristes turkayi n. sp.

( Figs 5–7 )

Paguristes sp. 3 Ayón-Parente & Hendrickx, 2010b: fig. 3, tab. 1, 2.

Type material. Holotype: male (SL 6.1 mm), Gorda Bank (23°08’5”N, 109°27’04”W), off Southern Baja California, Mexico, CORTES 1, st. 55, 13 May 1982, R / V “El Puma”, oyster dredge, 38 m (ICML-EMU-11426) . Paratype: Ovigerous female (SL 5.1 mm), Cocinas Islands (19°32’58.79”N, 105°06’45.71”W), Bay of Chamela , Jalisco, 03 Oct 2008, scuba diving, 10 m (ICML-EMU-11427) .

Description. Thirteen pairs of biserial gills. Shield ( Fig. 5A ) dorsally flattened, about 1.1 × as long as broad; anterolateral margins slightly slopping, anterior margin between rostrum and lateral projections concave; posterior margin truncated. Dorsal surface rugose anteriorly; lateral margins with few small spines and tufts of long setae. Anterolateral distal angle obtuse, ending in bifid spine. Rostrum long, slender, exceeding considerably lateral projections, with plumose setae distally. Lateral projections obtusely triangular, one marginal minute spine. Branchiostegites with row of small spines or spinules on anterodorsal and distal margins, concealed by tufts of long plumose setae.

Ocular peduncles ( Fig. 5A ) moderately long, 0.7 × as long as shield, cylindrical, with row of tufts of setae on dorsomesial surface. Cornea slightly dilated, corneal diameter equal to width of peduncle at its basis, 0.13–0.16 × peduncular length. Ocular acicles basally wide, subtriangular, ending in simple spine, lateral margin unarmed, acicles separated by 0.7 × basal width of one acicle.

Antennular peduncle ( Fig. 5A ) shorter than ocular peduncles, when fully extended reaching basis of cornea. Ultimate segment unarmed; penultimate segment with small spine on ventromesial margin in proximal half; basal segment with moderately strong spine on ventromesiodistal margin, distolateral margin unarmed, ventrolateral distal margin produced into elongate spiniform process.

Antennal peduncle ( Fig. 5A ) moderately long, reaching 0.67 × length of ocular peduncle, fifth segment with 3 small spines on proximal upper surface and few scattered tufts of setae; fourth segment with strong dorsodistal spine and setae; third segment with ventral margin strongly produced, ending in strong spine and tufts of long setae; second segment with dorsolateral distal angle strongly produced, ending in bifid spine, lateral margin unarmed with tufts of short setae, dorsomesial distal angle with 1 small spine, mesial margin setose; first segment with dorsolateral margin unarmed, ventral margin strongly produced, a small ventral, distal spine laterally and mesially. Antennal acicle moderately long, reaching to distal margin of fifth peduncular segment, terminating in prominent bifid spine, lateral margin with 1 or 2 spines, mesial margin with 3 spines, armatures partially obscured by long setae. Antennal flagellum reaching distal margin of palm, articles each with short setae (shorter than 1 article length) and 1–4 long setae (longer than 2 or 3 articles length).

Mandible without distinctive features.

Maxillule ( Fig. 6A ) with proximal (coxal) endite subquadrate, distal (basial) endite subrectangular, enlarged distally, with rigid setae on internal margin; endopod with 3 or 4 terminal bristles on weakly produced internal lobule, external lobule well developed, recurved, approximately 0.67 × length of endopod, outer angle with 3 long setae.

Maxilla ( Fig. 6B ) with endopod moderately long, proximal 1/2 somewhat inflated, distally exceeding scaphognathite, proximal and distal lobes of coxal endite with setae.

First maxilliped ( Fig. 6C ) endopod shorter than basial segment of exopod, epipod well developed.

Second maxilliped without distinct characters.

Third maxilliped ( Fig. 6D ) with 1 spine on coxa, basis-ischium fusion complete, basis with 2 small spines, ischium with crista dentata well developed, with 15 or 16 corneous teeth, without accessory tooth, merus with 3 spines on ventral margin, dorsodistal margin with 1 small spine, carpus with moderately strong spines at ventrolateral and dorsolateral distal margins, propodus and dactyl unarmed; exopod reaching distal margin of carpus.

Chelipeds ( Fig. 5B, C ) slightly unequal, right longer that left, similar in armature. Hand, carpus and merus flattened dorsoventrally. Dorsal surface of hand and carpus covered with long bristle-like setae. Dactyl nearly 2 × length of palm, dorsomesial margin with 2 irregular rows of strong, corneous-tipped spines decreasing in size distally, dorsal surface with 2 or 3 irregular rows of corneous-tipped spines, mesial surface with 2 longitudinal rows of corneous-tipped spines; ventral surface with row of corneous-tipped spines and tufts of long setae, cutting edges with calcareous teeth on proximal 2/3 interspaced with small corneous teeth, corneous teeth distally, terminating in small corneous claw overreached by fixed finger. Palm with 4 prominent spines on dorsomesial margin, dorsolateral margin with corneous-tipped spines decreasing in size distally and tufts of long setae, dorsal surface covered with numerous spines, extending on fixed finger, mesial surface with few corneous-tipped spines and tufts of long setae, ventral surface with numerous spines extending on fixed finger and scarcely tufts of long setae, cutting edge with calcareous teeth interspaced with small corneous teeth, corneous teeth distally, terminating in small corneous claw. Carpus trapezoid in dorsal view, 1.5 × length of palm, dorsomesial and dorsolateral margins not well defined, bearing corneous-tipped, moderately large conical spines, dorsal surface and dorsodistal margin with corneous-tipped spines, lateral face with scarce corneous-tipped spines and tufts of long setae, mesial face with scarce corneoustipped spines or flattened tubercles, ventral surface with tufts of long setae on distal margin. Merus with moderately large corneous-tipped spines on laterodistal margin and tufts of long setae; dorsal margin with tufts of short setae and few small pines distally, mesial face smooth with tufts of short setae, lateral face rugose, with numerous small corneous-tipped spines and tufts of short setae, ventromesial margin with scarce small spines, one large spine at ventromesiodistal angle, ventrolateral margin with spines increasing in size distally, ventral surface with tufts of long setae. Ischium with row of small spines or spinules and tufts of long setae on ventromesial margin.

Second and third pereopods ( Fig. 7A–C ) with dactyl 1.5–1.9 × length of propodus, dorsal margin with row of long bristle-like setae, dorsomesial margin with corneous-tipped tubular or conical spines proximally and corneous spine distally, concealed by tufts of long setae (second) or only corneous spines and tufts of long setae (third), dorsolateral margins with tufts of long setae, mesial faces with longitudinal sulcus shallower distally, and corneous spines (third), only on distal 1/3 (second), and tufts of long setae, lateral faces with tufts of long setae, ventromesial and ventrolateral margins with corneous spines and tufts of long setae, ventral margins with row of corneous spines concealed by tufts of long setae. Propodus 1.1–1.2 × length of carpi, dorsal surfaces with flattened tubercles and tufts of long setae, dorsomesial margins with row of corneous-tipped conical spines (second) or flattened tubercles (third) and tufts of long setae, dorsolateral margins with tufts of long setae, lateral faces with flattened tubercles and tufts of long setae; mesial faces with longitudinal deep sulcus (second) or shallow sulcus (third) and vertical rows of spine-like tubercles and tufts of long setae, ventral surfaces with flattened tubercles or spine-like tubercles and tufts of long setae. Carpus 0.7–0.8 × length of merus, dorsal surfaces with 2 or 3 irregular rows of moderately large spines (second) or with 3 or 4 spines, larger one distally (third), and tufts of long setae, lateral faces with weak longitudinal sulcus and 2 irregular longitudinal rows of small or moderately large spines on distal 2/3 (second) or only 2 distal spines (third) and tufts of short to moderately long setae, mesial faces with few small spines distally (second) or only tufts of long setae (third). Merus with dorsal row of low protuberances and tufts of moderately long setae, mesial faces bare or with scarce tufts of very short setae, lateral faces with small flattened tubercles and tufts of short setae, one small spine at ventrolateral angle (second), ventromesial margins with small distal spines and tufts of long setae, ventral margins with low protuberances and long setae. Ischium with tufts of long setae on dorsal and ventral margins.

Sternite XII (pereopods 3) rectangular, fringed anteriorly with tufts of long setae.

Pereopod 4 ( Fig. 7D ) propodal rasp well developed, 2–4 rows of ovate scales, dactyl 0.8 × length of propodus, 5 or 6 corneous spines posterior to claw, preungual process present, slender, carpus and merus unarmed, tufts of long setae on ventral and dorsal surfaces.

Pleopods 1 ( Fig. 7E, F ) modified in males; with tuft of long setae on upper mesial angle, mesial margin of basal lobe with long setae, mesial margin of the inferior lamella with row of long setae, distal margin with 2 rows of curved denticles; internal lobe moderately long, subrectangular, long setae on mesial margin and inferior surface; external lobe shorter than inferior lamella. Pleopods 2 missing. Pleopods 3–5 with well-developed exopod, endopod reduced or vestigial. In females, first pair of pleopods modified ( Fig. 6G ), basal segment bearing long setae on the mesial margin, distal segment marginalized with long feathery setae. Pleopods 2‒4 with both branches well developed. Pleopods 5 as in males. Brood pouch ( Fig. 5D ) subcircular, margins usually weakly scalloped on the anterior margin and fringed with long setae.

Telson ( Fig. 5E ) with asymmetrical posterior lobes, separated by V-shaped median cleft, left lobe larger than right, posterior margin of left lobe with 3 spines, right lobe with 1 or 2 smaller spines, lateral margins and anterior lobes unarmed, all with tufts of long setae.

Color. In alcohol, ocular peduncles pinkish, cornea black with remains of dark blue; chelipeds red with dorsal subdistal margin of merus and carpus yellow to cream. Ambulatory legs red, with numerous white or cream spots, and one yellow band distally on propodus, carpus and merus. Straw yellow setae.

Habitat. The specimens were collected on sandy substrate. The individuals were occupying shells of Conus brunneus W. Wood, 1828 . The ovigerous female bears eggs (diameter 0.92 mm) in early development stage.

Distribution. Known from Gorda Bank, Gulf of California, and Cocinas Islands, Bay of Chamela, Jalisco, Mexico; 10– 38 m.

Etymology. The species is named in honour of the late Michael Türkay, formerly head of the Marine Zoology Department, Senckenberg Institute, Germany, for his great contribution to our knowledge on crustaceans and his support to many carcinologists worldwide.

Remarks. Paguristes turkayi n. sp. is closer to P. sanguinimanus and P. digueti than to any other species of Paguristes known from the eastern tropical Pacific. These three species are characterized by a body that is dorsoventrally depressed, and the fifth antennal segment with spines. However, P. turkayi n. sp. can be easily differentiated from these two species. In Paguristes turkayi n. sp., the rostrum is more slender than in the other two species; the ocular peduncles are proportionally larger in relationship with the shield in P. turkayi n. sp. than in P. digueti , but shorter than in P. sanguinimanus . The armature of the chelipeds is also different; in P. turkayi n. sp. the spines on the palm and carpus are prominent and the setae very long, whilst in P. digueti and P. sanguinimanus the spines on the palm and carpus are small and the setae very short, barely matching the length of the spines, giving a bare appearance. The carpus and merus of the fourth pereopods in P. turkayi n. sp. and P. sanguinimanus are unarmed, while in P. digueti , there are 3 tipped-corneous spines on the dorsodistal margin of the merus, 1 strong, tipped-corneous spine on dorsodistal margin of carpus, and a row of 3 or 4 smaller spines on the dorsal surface. In Paguristes turkayi n. sp. the telson is armed with 3 small spines on the left lobe and 2 spines on the right lobe, instead of 6 and 4 in P. digueti and 4 or 5 in P. sanguinimanus .

Paguristes turkayi n. sp. also differs from P. digueti by the rostrum; in the latter it is shorter and barely reaches the base of the ocular acicles and is equal in length to the lateral projections. In P. digueti the anterodorsal plates of the carapace are armed with small denticles, while in Paguristes turkayi n. sp., these plates are unarmed.

Paguristes turkayi n. sp. features a depressed precervical portion and distention of the branchial regions, as well as of the abdomen. This is probably due to the type of shell used as shelter ( Conus brunneus ). Glassell (1938) mentions that in Paguristes digueti there is also a depression of the precervical portion and a distention of the branchial area as a consequence of the shell used as shelter ( Strombus sp. ).

Figures

FIGURE 5. Paguristes turkayi n. sp. A‒C, E, holotype male (ICML-EMU-11426). D, paratype ovigerous female (ICML-EMU- 11427).A, carapace and cephalic appendages in dorsal view; B, right cheliped, dorsal view; C, same, mesial view, setae omitted; D, brood pouch; E, telson, dorsal view. Scale: 5 mm.

FIGURE 6. Paguristes turkayi n. sp., holotype male (EMU-11426): A, maxillule; B, scaphognathite; C, first maxilliped; D, third maxilliped. Scale: 1 mm.

FIGURE 7. Paguristes turkayi n. sp.: A‒F, holotype male (ICML-EMU-11426); G, paratype ovigerous female (ICML-EMU- 114276). A, right second pereopod, mesial view; B, same in lateral view; C, right third pereopod, mesial view; D, dactyl, propodus and carpus of right fourth pereopod, lateral view; E, first male pleopod, inner view; F, same, outer view; G, first female pleopod. Scales: A‒C, 5 mm; D, 1 mm; E‒G, 0.5 mm.