Paratya compressa (De Haan, 1849)

Cai, Y., 2006, Atyid shrimps (Crustacea: Decapoda: Caridea) of the Ryukyu Islands, southern Japan, with descriptions of two new species, Journal of Natural History 40 (38 - 40), pp. 2123-2172 : 2125-2130

publication ID	https://doi.org/ 10.1080/00222930601084049
persistent identifier	https://treatment.plazi.org/id/039A9827-FF9D-FFFD-CBFB-89B2FE8AEB8F
treatment provided by	Felipe
scientific name	Paratya compressa (De Haan, 1849)
status

Treatment

Paratya compressa (De Haan, 1849) View in CoL

( Figures 1–3 View Figure 1 View Figure 2 View Figure 3 )

? Ephyra compressa De Haan, 1844, p 186 , pl. 46 [type locality: Japan].

Miersia compressa: Kingsley 1879, p 416 .

Xiphocaris compressa: Doflein 1902, p 631 View in CoL ; Rathbun 1902, p 49; Bouvier 1904, p 29 (part); 1905, p 61(part)

Xiphocaridina compressa: Bouvier 1909a, p 330 View in CoL (part); 1909b, p 328 (part); Balss 1914, p 23 (part).

Paratya compressa: Roux 1926a, p 238 View in CoL ; 1926b, p 187; Kubo 1938, p 68, figs. 2A, 3A–E; 1941, p 127; Lee 1958a, p 25; 1958b, p 1; Kamita 1958, p 13; 1961, p 11; 1963, p 4, fig. 2; Kim and Park 1973, p119; Kim 1976, p 137; Shokita and Nishijima 1977, p 187; Nishino 1981, p 201; Shokita et al. 2003b, p 117.

Paratya compressa compressa: Shokita 1975, p 119 View in CoL ; 1990, p 311; Hayashi 1989e, p 498, figs. a–f; Yamaguchi and Baba 1993, p 215, fig. 36; Ikeda et al. 1992, p 819; 1994a, p 37; 1994b, p 679; 1995a, p 69; 1995b, p 1; 1996, p 37; Shokita 2003, p 249, figs. 17A, 19E, 19H, 20E–G; Ikeda 1999, p 43; Page et al. 2005, p 584; Shokita et al. 2002b, p 76.

Not Paratya compressa: Kemp 1917, p 294 View in CoL , fig.1; 1918 p 293.

Material examined

One male, cl 5.4 mm, 1 female, cl 7.3 mm, ZRC 2004.0564 View Materials , upper stream of Tima River, about 4 km from river mouth, Okinawa Island, Ryukyu Islands , coll. Y. Cai, N. K. Ng, T. Naruse and S. Islam, 11 June 2000 ; 1 male, cl 5.6 mm, 1 female, cl 7.5 mm, 2 ovigerous females, cl 6.6–6.8 mm, URB, Henan River, Okinawa Island, Ryukyu Islands , 17 April 1999 ; 12 females, cl 3.5–6.8 mm, 3 males, cl 3.8–4.6 mm, Yakukachi River, Amamiohshima, Ryukyu Islands , 29 July 1992 ; 5 males, cl 5.0– 5.6 mm, 2 females, cl 5.3–7.1 mm, 5 juveniles, ZRC 2004.0565 View Materials , fast flowing water, upper part of Omija River, Iriomote Island, Ryukyu Islands , coll. Y. Cai and T. Naruse , 15 June 2000 ; 3 females, cl 7.2– 7.9 mm, ZRC 2004.0566 View Materials , Okuma River, Okinawa Island, Ryukyu Islands , 31 May 1998 . Comparative material examined

Paratya improvisa Kemp, 1917 View in CoL : two males, cl 5.5 mm, 1 female, cl 4.0 mm, NMST1222 , Natori-gawa River basin, Miyagi Prefecture, Japan, 27 July 1974; 1 male, cl 5.2 mm, NMST1688 , Natori-gawa River , Miyagi Prefecture, coll. M. Nakamura 27 July 1974 ; 1 ovigerous female, cl 6.9 mm, NMST1540 , the junction of Natori-gawa River and Goishigawa River, northeast of Honshu, Japan, 27 July 1974 .

Description

Rostrum ( Figures 1A View Figure 1 and 3A View Figure 3 ) reaching to or slightly beyond end of scaphocerite, dorsal margin nearly horizontal, or slightly sigmoid, armed with 16–25 (mode 17–24) teeth throughout dorsal margin, two or three of them situated on carapace posterior to orbital margin, armed ventrally with one to six (mode one to three) teeth. Antennal spine slightly lower than inferior orbital angle; pterygostomian margin subrectangular.

Sixth abdominal somite 0.65 times length of carapace, 1.6 times as long as fifth somite, subequal to length of telson. Telson ( Figure 1B,C View Figure 1 ) 3.2 times as long as wide, not terminating in a posteromedian projection, with two pairs of dorsal spinules and one pair of dorsolateral spinules; dorsal pairs situated near edges; distal end broadly rounded, with about 11 setae, lateral pair slightly longer than intermediates. Preanal ( Figure 1J View Figure 1 ) carina with a spine.

Eyes well developed, anterior end reaching to 0.8 times length of basal segment of antennular peduncle. Antennular peduncle 0.70 times as long as carapace; basal segment of antennular peduncle distinctly longer than sum of second and third segment lengths, anterolateral angle reaching 0.30 times length of the second segment, second segment distinctly longer than third segment. Stylocerite reaching to 0.7 times length of second segment of antennular peduncle. Scaphocerite ( Figure 1D View Figure 1 ) 3.0 times as long as wide.

Incisor process of mandible ( Figure 1E View Figure 1 ) ending in irregular teeth, molar process truncated. Lower lacinia of maxillula ( Figure 1F View Figure 1 ) broadly rounded, upper lacinia elongate, with a number of distinct teeth on inner margin, palp slender. Upper endites of maxilla ( Figure 1G View Figure 1 ) subdivided, palp short, scaphognathite tapering posteriorly with numerous long, curved setae at posterior end. Palp of first maxilliped ( Figure 1H View Figure 1 ) ending in a fingerlike projection. Second maxilliped ( Figure 1I View Figure 1 ) typical. Third maxilliped ( Figure 2A View Figure 2 ) reaching to end of antennular peduncle, with ultimate segment slightly shorter than penultimate segment.

Epipods on first four pereiopods. Exopod on all pereiopods. First pereiopod ( Figures 2B View Figure 2 and 3B View Figure 3 ) reaching to distal end of eyes; merus 3.2 times as long as broad, as long as carpus; carpus excavated anteriorly, shorter than chela, 1.6 times as long as high; chela 1.6 times as long as broad; fingers shorter than palm. Second pereiopod ( Figures 2C View Figure 2 and 3C View Figure 3 ) reaching to end of second segment of antennular peduncle; merus shorter than carpus, 5.0 times as long as broad; carpus longer than chela, 5.0 times as long as high; chela 3.0 times as long as broad; fingers slightly longer than palm. Third pereiopod ( Figures 2D,E View Figure 2 and 3D,E View Figure 3 ) reaching to end of scaphocerite, propodus 11 times as long as broad, 4.2 times as long as dactylus; dactylus 2.1 times as long as wide (spines included), terminating in one claw, with five to seven accessory spines on flexor margin. Fifth pereiopod ( Figures 2F,G View Figure 2 and 3F,G View Figure 3 ) reaching slightly beyond end of second segment of antennular peduncle, propodus 11 times as long as broad, 4.3 times as long as dactylus, dactylus 2.7 times as long as wide (spinules included), terminating in two claws, with 61 spinules on flexor margin.

Endopod of male first pleopod ( Figure 3H View Figure 3 ) elliptical, 2.2 times as long as wide, one quarter length of exopod; appendix interna elongated, with most of its length reaching beyond distal end of endopod. Appendix masculina of male second pleopod ( Figure 3I View Figure 3 ) very small, appendix interna much longer than appendix masculina.

Uropodal diaeresis ( Figure 1K View Figure 1 ) with 1 movable spinule.

Eggs 0.35–0.45× 0.24–0.30 mm in diameter.

Habitat

Lower reaches of rivers and streams which discharge to the sea.

Remarks

De Haan (1849) described Paratya compressa under the name of Ephyra , from Japan with no specific locality being mentioned. Nishino (1981) showed the distributions of two forms of P. compressa , one with a large egg, in central Honshu and the other, with a small egg, in southern Japan. Specimens reported by Kemp (1917) as Paratya compressa are most probably an undescribed species. According to Kemp (1917, p 296), his material was from Komatsu Lake near the eastern shore of Lake Biwa and from the Ogura and Yodo ponds near Kyoto, Honshu. ‘‘The dactylar spines (of third pereiopod) vary in number from 19 to 22, very rarely 18. In the fifth pereiopods (text figs. Ie, f) the propodus is also from 2.1 to 2.5 times as long as dactylus.’’ This description, however, is very different from the type material of P. compressa . Dr. C. Fransen, curator of the Leiden Museum, checked the syntypes on the request of the first author, as they are all too fragile to be posted. Result of his examination revealed that of the eight syntypes of Paratya compressa (RMNH D1007) , ‘‘only two specimens have a third pereiopod attached. In one specimen the ratio propodus/dactylus (of third pereiopod) is 4.7, the number of spines on the carpus of the dactylus (of third pereiopod) seven. In the other (smaller) specimen, the ratio propodus/dactylus is 4.0 and the number of spines on the carpus of the dactylus five’’ (C. Fransen, pers. commun.). A review study on the basis of specimens from the whole distribution range is necessary to clarify their identities.

Kemp (1917) proposed a subspecies Paratya compressa improvisa ( Figure 4 View Figure 4 ) for the specimens from Lake Haruna, Honshu Island, Japan. It differs from the nominal subspecies mainly on the basis of the rostral teeth arrangement. It has no teeth on the carapace while those of P. compressa have two to three. But as shown in Figures 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 , the propodus and dactylus of the male third pereiopods are very different in the two subspecies and very easy to separate from each other, we hereby recognize both as distinct species.

Distribution

Southern Japan.

T	Tavera, Department of Geology and Geophysics
URB	Ryukyu University Department of Zoology

Copyright notice

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Taxonomy

Kingdom	Animalia
Phylum	Arthropoda
Class	Malacostraca
Order	Decapoda
Family	Atyidae
Genus	Paratya