Periclimenes guarapari, Grave, De, 2008

Grave, De, 2008, A new species of Periclimenes (Crustacea: Decapoda: Palaemonidae) from Guarapari, Espirito Santo, Brazil, Zootaxa 1925, pp. 14-22 : 15-20

Periclimenes guarapari sp. nov.

( Figs. 1–5 )

Material examined: Holotype ovigerous female (pocl 2.1mm), from Muricea flammea , Ilha Escalvada, in front of Guarapari City, Espirito Santo, Brazil, 17m depth, approximately 20º42’S 04º24’W, leg. P. Wirtz, 29 April 2006 ( MZUSP 18837); paratypes (17 ex., pocl 1.0– 2.1 mm), same data as holotype ( MZUSP 18838); paratypes (7 ex., pocl 1.6–2.1 mm), same data as holotype (OUMNH-ZC. 2008-12 -001); paratypes (7 ex., 1.2– 1.7 mm) from Plexaurella grandiflora , Ilha Escalvada, in front of Guarapari City, Espirito Santo, Brazil, 17m depth, approximately 20º42’S 04º24’W ( RMNH D53043), leg. P. Wirtz, 30 April 2006.

Derivation of name: Named after the type locality, the city of Guarapari , state of Espirito Santo, Brazil, used as a noun in apposition.

Description: Small pontoniine shrimp, adults attaining approximately 1.3–2.1 mm post-orbital carapace length (pocl). Rostrum relatively deep, not upturned ( Figs. 1 A, C), extending to end of second segment of antennular peduncle; dorsally armed with 5–8 teeth, ventrally with 0–2 vestigial teeth; proximal dorsal tooth separated from remainder of series by considerable gap, situated proximal to hepatic tooth; second tooth nearly even with or slightly distal to posterior margin of ocular orbit. Carapace with well developed antennal and hepatic teeth, antennal tooth separated from lower margin of ocular orbit; hepatic tooth slightly larger than antennal tooth.

Abdominal pleura rounded ( Fig. 1 D), sixth abdominal somite twice as long as fifth, lateral plate bluntly angular, unarmed.

Eye ( Fig. 1 B) with cornea as wide as stalk, constricted at base; accessory pigment spot present, not facetted.

Antennular flagellum ( Fig. 2 A) with lateral flagella fused for 4–5 segments, ventral branch with 3–4 free segments; 4 aesthetascs on the last two fused articles and along the free part of the ventral branch. Antennular peduncle with only 1 tooth on distolateral angle of basal segment. Antennal scale ( Fig. 2 B) 3.5 times as long as wide, lateral margin straight; distolateral tooth falling short of distal margin of blade.

Mandible ( Fig. 2 C) lacking palp, incisor process ending in 4 distinct teeth, mesial margin with 3 smaller teeth; molar process as illustrated. Maxillule ( Figs. 2 D–E) with upper endite harbouring 5–6 stout, apical setae, interspersed with plumose setae, palp as illustrated. Maxilla ( Fig. 2 F) with bilobed endite. First maxilliped ( Fig. 2 G) with well-developed exopodal flagellum possessing 3 terminal plumose setae, epipod not bilobed; palp slender, lacking terminal setae. Second maxilliped ( Fig. 2 H) possessing well developed exopod with terminal setae. Third maxilliped ( Fig. 2 I) with basis separated from ischiomerus; exopod well-developed, falling short of distal margin of carpus.

First pereiopod ( Fig. 3 A) stout, not extending beyond antennal scale; fingers of chelae equal in length to palm, cutting edges lacking teeth; chelae approximately equal to carpus in length, merus subequal to carpus in length. Second pereiopods ( Figs. 3 B–C) unequal in size and length, extending beyond antennal scale. Chela of minor second pereiopod ( Fig. 3 B) with fingers approximately equal in length to palm, cutting edges simple, tips single; chela 1.3 times as long as carpus, merus subequal to carpus, ischium subequal to merus, latter imperfectly divided into two articles. Major second pereiopod robust ( Fig. 3 C), merus and ischium subequal, ischium imperfectly divided into two articles; chela twice as long as carpus, fingers of chela half length of palm; fingers of chela with single tips, cutting edge of pollex armed with single tooth in proximal third, cutting edge of dactylus armed with single tooth, margin mesially excavated ( Fig. 3 D).

Third and fourth pereiopod ( Fig. 3 E–F) with biunguiculate dactyli ( Fig. 4 A), unguis demarcated, similar to each other in size and structure; propodi nearly 4 times length of dactyli, distal margin of flexor margin armed with, respectively, 4 and 3 single teeth; distolateral angle with pair of spines ( Fig. 4 A); carpi half length of propodi, meri subequal to propodi. Fifth pereiopod ( Fig. 3 G) smaller than preceding ones, propodus 4 times as long as dactylus, carpus half length of propodus, merus subequal in length to propodus; flexor margin of propodus armed with 3 single spines, distolateral margin with single spine ( Fig. 4 B), setal brush poorly developed, consisting of 2 rows, with 4–5 comb-like setae each.

Uropods typical of the genus; exopod distinctly broader and longer than endopod, 0.3x longer than telson, distolateral tooth and associated movable spine well-developed, transverse suture indistinct. Telson approximately 3 times as long as wide; dorsolateral spines distinct ( Fig. 4 C), proximal pair inserted at mid-length of telson, distal pair at 0.75; distal margin of telson ( Fig. 4 D) with 2 pairs of spines and one (mesial) pair of plumose, stout setae, intermediate spines longest; terminal process between mesial pair of setae well-developed.

Second pleopod of male with appendices masculina and interna on endopod ( Fig. 4 E), appendix masculina shorter than interna, provided with 2 distal and 1 subdistal serrulate setae.

Colour pattern ( Fig. 5 ): Largely transparent, with scattered red chromatophores on abdomen, telson and uropods; distinctive transverse line of red chromatophores across first pleonite; legs transparent; antennae translucent.

Ecology: The type series was collected from the gorgonians, Muricea flammea Marques & Castro and Plexaurella grandiflora Verrill (Octocorallia, Alcyonacea , Plexauridae ), at depths ranging from 10 to 17m, together with Neopontonides beaufortensis (Borradaile, 1920)

Distribution: Currently known only from the type locality.

Figures

FIGURE 1. Periclimenes guarapari sp. nov. A lateral view (holotype); B eye (paratype female pocl 1.8 mm); C carapace (paratype female pocl 1.8 mm); D abdominal segments 4 – 6 (holotype); E rostrum (male, pocl 1.3 mm); F rostrum (male, pocl 1.5 mm); G rostrum (female, pocl 1.6 mm); H rostrum (female, pocl 1.6 mm); I rostrum (female, pocl 1.8 mm). Scale bar indicates 0.6 mm (A) or 1 mm (B – I).

FIGURE 2. Periclimenes guarapari sp. nov. A antennule; B antennal scale; C right mandible; D maxillule; E maxillule, palp; F maxilla; G first maxilliped; H second maxilliped; I third maxilliped. All from female paratype (pocl 1.8 mm). Scale bar indicates 0.25 mm (A), 0.35 mm (B) or 0.50 mm (C – I).

FIGURE 3. Periclimenes guarapari sp. nov. A first pereiopod; B minor second pereiopod; C major second pereiopod; D same, chela; E third pereiopod; F fourth pereiopod; G fifth pereiopod. All from ovigerous female paratype (pocl 1.8 mm). Scale bar indicates 0.5 mm (A – C, E – G) or 0.17 mm (D).

FIGURE 4. Periclimenes guarapari sp. nov. A third pereiopod, distal part; B fifth pereiopod, distal part; C telson; D same, tip; E endopod of second pleopod. A – D from ovigerous female paratype (pocl 1.8 mm), E from male paratype (1.3 mm). Scale bar indicates 0.25 mm (A – B, D – E) or 0.35 mm (C).

FIGURE 5. Periclimenes guarapari sp. nov. on Muricea flammea at Ilha Escalvada, in front of Guarapari city, Espirito Santo, Brazil (specimen not part of type series). Photo by J. P. Cauduro Filho.