Micratya poeyi (Guèrin-Méneville, 1855), Guerin-Meneville, 1855

Karge, Andreas, Page, Timothy J. & Klotz, Werner, 2013, A new species of freshwater shrimp of the genus Micratya (Decapoda: Atyidae: Caridea) from Puerto Rico, Zootaxa 3608 (5), pp. 357-368 : 359-362

Micratya poeyi (Guèrin-Méneville, 1855)

( Figs. 3 A–M, 4O–X, 7B)

Atya Poeyi Guérin-Méneville, 1855 Calmania poeyi Bouvier, 1909 b

Material examined. Neotype female, (MNHN-IU-2011-6056), Cuba, leg. P. Serre, 1909; Others: 2 females (MNHN-Na610, MNHN-Na613); 1 male (MNHN-Na612), Cuba, leg. P. Serre, 1909; 1 male, cl 4.1 mm; 2 ov. females, cl 5.8–6.7 (MNHN-IU-2011-6066), Río Guanajibo, Puerto Rico; 1 ov. female, cl 6.2 (MNHN-IU-2011- 6065), Río Guanajibo, Puerto Rico; 2 ov. females, cl 6.2–6.3 mm, (MNHN-IU-2011-6064), Río Grande de Manatí, Puerto Rico; 1 ov. female, cl 6.7 (MNHN-IU-2011-6062), Río Espirutu Santo, Puerto Rico, leg. B.D. Cook, J. Hughes and P. Hernandez-Garcia, February 2006; 1 male, cl 3.39 mm, (MNHN-IU-2011-6063), Oropuche River, Trinidad, leg. C. Rogers.

Diagnosis. Rostrum ( Fig. 3 A, 3B) short, reaching near to end of basal segment of antennular peduncle, 0.22–0.29 times as long as carapace, armed dorsally with 7–9 teeth including 0–2 (most 0) on carapace posterior to orbital margin, 1 or 2 ventral teeth. Pterygostomial angle broadly rounded. Inferior orbital angle fused with antennal spine. Antennular peduncle 0.41–0.52 times as long as carapace, with a very small (0.15–0.21 times as long as second segment of antennular peduncle) or rudimentary tooth. Stylocerite 0.79–0.88 times as long as the basal segment of antennular peduncle. Incisor process of mandible ( Fig. 3 M) ending in irregular teeth, molar process truncated. Lower lacinia of maxillula ( Fig. 3 L) broadly subrectangular, upper lacinia elongate, with numerous distinct teeth on inner margin, palp slender with few simple setae at tip. Upper endites of maxilla ( Fig. 3 K) subdivided, palp slender, scaphognathite tapering posteriorly, fringed with long, curved setae at posterior margin. Palp of first maxilliped ( Fig. 3 I, J) ending in an elongated triangular projection. Podobranch on second maxilliped ( Fig. 3 H) well developed. Third maxilliped ( Fig. 3 G) with 1 well developed and 1 rudimentary arthrobranch, ultimate segment as long as penultimate segment. Pleurobranchs present on first to fourth pereiopod. First pereiopod without arthrobranch. Well developed epipods present on third maxilliped and first 3 pereiopods. Carpus of first pereiopod ( Fig. 4 O) 0.76–1.00 times as long as wide, distally excavated; chela 2.78–3.75 times as long as wide; dactylus 5.56–8.18 times as long as wide; tips of fingers rounded, no visible palm. Merus of first pereiopod 0.79–0.87 times as long as chela and 1.36–1.67 times long as carpus. Carpus of second pereiopod Fig. 4 P) 1.06–1.08 times as long as wide; chela 2.48–2.83 times as long as wide, 1.72–1.95 times length of carpus; dactylus 5.54–5.83 times long as wide; tips of fingers rounded. Merus of second pereiopod 1.08–1.21 times as long as chela and 2.08–2.11 as times long as carpus. Dactylus of third pereiopod ( Fig. 4 Q-T) 1.85–3.17 times as long as wide (terminal spine included), terminating in 1 large claw and 4–5 spines on flexor margin, second spine very small; propodus 5.29–7.86 times long as wide, 2.89–3.36 times as long as dactylus. Fifth pereiopod ( Fig. 4 U,V) slender, dactylus 2.63–3.30 times as long as wide (terminal spine included), with 1 large claw and 24–43 spines on flexor margin (most 36-38); propodus 7.80–11.14 times as long as wide, 3.55–4.59 long as dactylus. Endopod of male first pleopod ( Fig. 4 W) elongated, 2.0 times as long as proximal width. Appendix interna strong, 0.69 long as first endopod. Endopod of male second pleopod ( Fig. 4 X) 4.76 as long as wide. Appendix masculina ( Fig. 4 X, 7B) 0.84 as long as endopod. Appendix interna of second pleopod reaching to 0.62 length of appendix masculina. Spinulation of appendix masculina near distal end, tip of appendix interna not reaching to the spinulated part of appendix masculina. Sixth abdominal segment 0.38–0.43 times length of carapace. Telson ( Fig. 3 E, F) 2.29–2.48 times as long as proximally wide, posterior margin rounded, with median projection, with 5–7 pairs of dorsal and 1 pair of dorsolateral spinules; distal end with 7–8 pairs spines, 6–7 intermediate pair with fine bristles, longer and thinner than lateral spines. Preanal carina ( Fig. 3 C) rounded, with distinctly tooth. Uropodal diaeresis with 20–23 movable spinules. Egg size of overigerous females 0.28–0.35 x 0.48–0.58 mm.

Distribution. Micratya poeyi is known from Great and Lesser Antilles: Cuba, Jamaica, Puerto Rico, Dominica, Martinique. A single ovigerous female was collected by D.P. Kelso in Costa Rica in 1964. F.A. Chace jr. (1983) reported Micratya poeyi from Panama as well Abele & Kim (1989) and Torati et al. (2011).

Remarks. The original type specimen described by Guérin-Méneville originated from a collection of Cuban material without further specification. The description as Atya poeyi by Guérin-Méneville comprises only a few sentences without accurate information on body proportions or details on spinulation of appendages. Most of the collections described by F.E. Guérin-Méneville are deposited in the Academy of Natural Sciences of Philadelphia but M. poeyi is not cataloged here (Spamer & Bogan, 1994). In the Oxford University Museum of Natural History, where a part of the collections are also deposited, no specimen of this species could be found (S. De Grave, personal communication). Two attempts to locate this type material at the Muséum national d’Histoire naturelle Paris were also unsuccessful (Laure Corbari & Paula Martin Lefevre, personal communication). Thus the type series seem to be lost. To stabilize taxonomy, a neotype was designated here for a specimen selected from the Cuban collections of P. Serre, deposited in the Muséum national d’Histoire naturelle Paris. Specimens from this collection had also been used by E.-L. Bouvier for his studies, which resulted in the description of the genus Micratya .

The examined specimens of Micratya poeyi indicate a sexual dimorphism. In addition to the smaller body size of males (cl. 3.65–4.1 in males vs. 6.2–6.7 in females), the two sexes differ in proportions of propodus on third pereiopod (7.86 times as long as wide in males vs. 5.29–6.00 in females); dactylus on third pereiopod (3.17 times as long as wide in males vs. 1.85–2.27 times in female) and the propodus on fifth pereiopod (11.14 times as long as wide vs. 7.80–9.36). This is the first time that a sexual dimorphism in Micratya poeyi has been reported.

Figures

FIGURE 3. Micratya poeyi, male (cl 3.39 mm) (MNHN-IU- 2011 - 6063): A. cephalothorax, B. rostrum, D. uropodal diaeresis, F. telson, G. third maxilliped, H. second maxilliped, I. first maxilliped, J. palp of first maxilliped, K. maxilla, L. maxillula, M. mandible; ovigerous female (cl 6.0 mm) (MNHN-IU- 2011 - 6064): C. preanal carina, E. telson, F. posterior portion of telson. Scale bars indicate 2.0 mm (A), 1.0 mm (B, E, G, K) 0.5 mm (C, D, F, H, I, L, M), without scale (J).

FIGURE 4. Micratya poeyi, male (cl 3.39 mm) (MNHN-IU- 2011 - 6063): O. first pereiopod, P. second pereiopod, Q. third pereiopod outer view, R. dactylus of third pereiopod outer view, S. third pereiopod inner view, T. dactylus of third pereiopod inner view, U. fifth pereiopod, V. dactylus of fifth pereiopod, W. male first pleopod, X. male second pleopod. Scale bars indicate 1.0 mm (O, P, Q, S, U), 0.5 mm (R, T, W, X), without scale (V).