Axius stirhynchus Leach, 1815

Ngoc-Ho, Nguyen, 2003, European and Mediterranean Thalassinidea (Crustacea, Decapoda), Zoosystema 25 (3), pp. 439-555 : 447-451

Axius stirhynchus Leach, 1815

( Figs 1 ; 2 )

Axius stirynchus Leach, 1815: 343 ; 1816: pl. 33. — Bell 1846: 228, 1 fig. — White 1847: 70; 1850: 32. — Stebbing 1893: 187. — Holthuis 1962: 252. — Sinel 1907: 217.

Axiopsis mediterranea Caroli, 1921a: 254 , fig. 1, pl. 9 figs 1-4, pl. 10 figs 5-16.

Callianassa bisulcata Risso , no date: Ms, fig. (f).

Axia stirhynchus –? Gibert i Olivé 1920: 51, 1 fig.

Axiopsis (Axiopsis) mediterranea – de Man 1925b: 70.

Axius stirhynchus – Desmarest 1825: 207, pl. 36 fig. 1. — H. Milne Edwards 1837a: 311; 1837b: 131, pl. 48 fig. 2. — White 1857: 25. — Norman 1868: 177; ° 1907: 357. — Carus 1885: 490. — Lovett 1885: 16. — Koehler 1886: 59. — Norman & Scott 1906: 13. — Norman 1907: 357. — Sinel 1907: 217. — Schlegel 1912: 237. — Selbie 1914: 89, pl. 14 figs 1-4. — Caroli 1921a: 254; 1921b: 241. — * Webb 1921: 406, pl. 3 figs 3, 6. — Monod 1931: 119, 123, fig. 6E. — ° Delphy & Magne 1938: 84. — Bouvier 1940: 93, fig. 65. — Zariquiey Alvarez 1946: 103, fig. 131; 1968: 223, fig. 88a. — Drensky 1951: 213. — * Kurian 1956: 72, fig. 141. — Gordon 1957: 249. — *Bourdillon-Casanova 1960: 99, fig. 35. — Holthuis 1962: 247; 1977: 57, pl. 5, fig. a. — * O’Céidigh 1962: 163. — ICZN 1964: 341. — Bourdon 1965: 15. — Allen 1967: 17, 57 (key), 89 (fig.). — ° Števčić 1969: 128; 1990: 214. — * Thiriot 1976: 349, 367. — Beaubrun 1979: 69, figs 44, 73. — Moncharmont 1979: 69. — d’Udekem d’Acoz 1986: 101, fig. 1; 1989: 175; 1995: 47, fig. 1; 1999: 153, fig. on cover. — Sakai & de Saint Laurent 1989: 27, fig. 7. — Moyse & Smaldon 1990: 517, fig. 10.12. — Dworschak 1992: 214. — ° Koukouras et al. 1992: 223. — Froglia 1995: 7. — Hayward et al. 1995: 432, fig. 8.51 (part). — Falciai & Minervini 1996: 143, 1 fig. — * Barnich 1996: 130, figs 28, 66. — Astall et al. 1997b: 668. — Pinn et al. 1999a: 103, figs 1H, 2A; 1999b: 1461, figs 1B, 4, tabls 1-6. — *González-Gordillo et al. 2001: 279. — Livory 2001: 30. — * Martin 2001: 75, 1 fig. — ° Türkay 2001: 289.

Axius (Axius) stirhynchus – Borradaile 1903: 537. — de Man 1925b: 11.

TYPE MATERIAL. — Lectotype: Plymouth, Devonshire , south coast of England, dried (figured by Leach 1815) ( NHML 261 b); paralectotype: Sidmouth, Devonshire, 1 dried ( NHML 261 a), by present designation.

MATERIAL EXAMINED. — Great Britain. Plymouth, Devonshire , lectotype cl. 20.5 mm, tl. 70.5 mm ( NHML 261 b) ; Sidmouth, Devonshire , paralectotype cl. 10.5 mm, tl. 33 mm ( NHML 261 a) .

France. English Channel, French coast, Pointe du Château, N of Tréguier ( Côtes d’Armor ), intertidal, P. Noël coll., 28.II.1994, 1 cl. 22.5 mm, tl. 70 mm, 1 cl. 20.5 mm, tl. 63.5 mm (figured) ( MNHN Th 1322) ; P. Noël and C. d’Udekem d’Acoz coll., 27.II.1994, 1 cl. 14 mm ( MNHN Th 1408). — Cherbourg, dredge, in mud, S. Godefroy coll., 11.XI.2001, 1 cl. 21 mm, tl. 64 mm ( MNHN Th 1414). — Dinard, Baron de St Joseph coll., 2 cl. 20 mm, tl. 61.5 and 62 mm (figured) ( MNHN Th 151). — St-Vaast-la-Hougue, Bouvier coll., 1 damaged ovigerous ( MNHN Th 150). — Bay of Mont- St-Michel, Y. Gruet coll., 24.IV.1967, 1 cl. 9 mm ( MNHN Th 611). — Locality?, Gruet coll., 31.I.1968, 1 cl. 7.5 mm ( MNHN Th 606) ; Gruet coll., 13.XII.1966, 1 cl. 8.5 mm ( MNHN Th 608) ; Gruet coll., 8.VIII.1962, 1 young cl. 7 mm ( MNHN Th 624). — Gruet coll., locality, date?, 1 cl. 12.5 mm ( MNHN Th 627). — North coast of Brittany, Bourdon coll., 1 broken cl. 15 mm ( MNHN Th 540) .

Atlantic, Chausey Island, under rock, intertidal, A. Crosnier, B. Richer de Forges , R. Manning coll., 28.VIII.1992, 1 young cl. 13 mm, tl. 36 mm (figured) (MNHN Th 1321) ; J.-C. Hureau and C. Ozouf coll., 28.III.1994, 1 cl. 14.5 mm (MNHN Th 1409). — West of Chausey Island, under rocks, A. Crosnier, B. Richer de Forges , P. Clark, R. Manning coll., 28.VIII.1992, 1 ( NHML 1992.1344 ) .

DISTRIBUTION. — Atlantic: southwest of Scotland ( Allen 1967), Ireland ( Selbie 1914; O’Céidigh 1962), southwest of North Sea (d’Udekem d’Acoz 1996). English Channel, English coast ( Norman 1868; Leach 1815; Norman & Scott 1906; Gordon 1957); English Channel, French coast ( Martin 2001). Atlantic: Chausey Island; French coast of the Bay of Biscay ( Delphy & Magne 1938);?Atlantic coast of Morocco ( Beaubrun 1979).

Mediterranean: south of Catalonia (Gibert i Olivé 1920), Banyuls ( Thiriot 1976), Nice ( Holthuis 1977), bay of Naples ( Caroli 1921a), Adriatic ( Dworschak 1992; Kurian 1956), Aegean sea ( Drensky 1951).

A distribution map was presented by d’Udekem d’Acoz (1996).

DIAGNOSIS

Rostrum ( Fig. 1D ) with blunt apex, four to six small round teeth on lateral margin, latter continued posteriorly to unarmed lateral carina. Eye with cornea rounded, well pigmented. Gastric region slightly convex, cervical groove present to whole length; median carina terminating distally near tip of rostrum, posteriorly near anterior third of gastric region, two short submedian carinae. Abdominal pleuron 1 pointed ventrally in young specimens ( Fig. 1A ) rounded in large ones; pleuron 2 broadest, pleura 3-5 with lateral tufts of setae; thoracic sternite of P4 unarmed or with minute lateral spine ( Fig. 1I ). Telson ( Fig. 1E ) slightly longer than wide, pair of dorsal spines on posterior half, convex posterior border with median spine.

A2 acicle large ( Fig. 1K ) reaching middle of fourth article of peduncle. Md ( Fig. 1H ) cutting edge smooth. Mx1 ( Fig. 1F ) endopod with distal article sickle-shaped; Mx2 ( Fig. 1G ) scaphognathite bearing pair of long posterior setae. Mxp1 ( Fig. 2A ) endopod slender, exopod with distal flagellum, epipod with large posterior lobe. Mxp2 ( Fig. 2B ) exopod with distal flagellum overreaching distal border of merus. Mxp3 ( Fig. 2C ) endopod carrying prominent ischial toothed crest ( Fig. 2D ), one or two lower distal spines on merus; exopod with distal flagellum.

P1 ( Fig. 1B, C ) slightly stouter in male than in female, unequal; larger cheliped with fixed finger and dactylus both bearing triangular tooth near middle of cutting edge; smaller cheliped with fixed finger bearing round and acute teeth on cutting edge, dactylus unarmed. P2 ( Fig. 2H ) chelate, fixed finger and dactylus with pectinate cutting edge. P3 ( Fig. 2I ), P4 ( Fig. 2J ) simple, latter with small spiniform setae on lateral surface of propodus and dactylus. P5 ( Fig. 2K ) subchelate.

Male Plp1 ( Fig. 2E ) small, unsegmented; male Plp2 ( Fig. 2F ) with appendix interna and appendix masculina. Female Plp1 ( Fig. 1L ) two-segmented; female Plp2 ( Fig. 1M ) with appendix interna. Male and female Plp3-5 ( Fig. 2G ) with appendix interna.

Uropod ( Fig.1E ) endopod and exopod about as long as telson with spinules on lateral external border, an unconspicuous suture near posterior border of exopod.

Colour

General colour: pale reddish-brown ( Bell 1846). Dull pink (d’Udekem d’Acoz pers. comm.); a colour photograph is presented in d’Udekem d’Acoz (1999: cover).

Size

Largest specimens in material examined: cl. 20.5- 22.5 mm, tl. 63.5- 70 mm. Largest size reported: tl. 72 mm ( Selbie 1914; Moyse & Smaldon 1990).

ECOLOGY AND BIOLOGY

This species is known as difficult of capture as it retreats to its burrows when disturbed (d’Udekem d’Acoz 1995). It occurs intertidally from Fucus serratus zone to about 34 m depth where it burrows in coarse muddy sand with the entrance often hidden under a large rock (d’Udekem d’Acoz 1995, 1999). It is rare in the Atlantic, uncommon in the British Isles ( Moyse & Smaldon 1990), very rare in the Mediterranean. It is found in Plymouth under stone in mud where its larvae occur in the plankton in summer and early autumn ( Gordon 1957). The species spawns at Roscoff, France, in July and August ( Schlegel 1912). Larvae are rare in the plankton of Roscoff but are more frequent in Banyuls, France, in summer ( Thiriot 1976), and common in July-September, off the French coasts of the English Channel ( Martin 2001).

The branchial morphology, gill area and gill ultrastructure were dealt with by Astall et al. (1997b); the diet by Pinn et al. (1998b); the gut morphology and gut microflora by Pinn et al. (1999a); mouth part setal fringes by Pinn et al. (1999b).

REMARKS

An amendation to stirhynchus of the original incorrect spelling stirynchus was proposed to the ICZN by Holthuis (1962) and validated under the plenary powers ( ICZN 1964).

The species has been quoted by several authors as having no suture on the uropod exopod. A suture actually exists, as revealed by Bouvier (1940) and Sakai & de Saint Laurent (1989) but is often inconspicuous and placed near the posterior bor- der of the exopod.

An illustration of this species from Nice in Risso’s manuscript notes, under the name Callianassa bisulcata , was discussed by Monod (1931) and Holthuis (1977). Both contended that Risso’s figure (fig. f) could hardly represent any other species in the area than Axius stirhynchus . The telson, correctly depicted with a convex posterior border and a pair of dorsal spines, confirms this view.

Figures

FIG. 1. — Axius stirhynchus Leach, 1815; A, young from Chausey, France (MNHN Th 1321), lateral view; B, C, E-H, J-M, from Pointe du Château, N of Tréguier, France (MNHN Th 1322); D, I, from Dinard,France (MNHN Th 151); B, C, right and left pereopod 1; D, anterior part of carapace; E, telson and uropods; F, G, maxillule and maxilla; H, mandible; I, thoracic sternite 4, ventral view; J, K, antennule and antenna; L, M, female pleopod 1-2. Scale bars: 2 mm.

FIG. 2. — A-K, Axius stirhynchus Leach, 1815, from Pointe du Château, N of Tréguier,France (MNHN Th 1322); A-D, H-K,; E-G,; A, B, maxilliped 1 and 2; C, D, maxilliped 3 and mesial view of ischium; E-G, male pleopod 1-3; H-K, pereopod 2-5; L-S, Calocarides coronatus (Trybom, 1904), from Bohuslan, Sweden (SMNH 5221); L, M, P-S,; N, O,; L, antennule; M, maxillule; N, O, female pleopod 1 and 2; P, Q, male pleopod 2 and 3; R, maxilla; S, antenna. Scale bars: 2 mm.