Calocarides Wollebaek, 1909

Ngoc-Ho, Nguyen, 2003, European and Mediterranean Thalassinidea (Crustacea, Decapoda), Zoosystema 25 (3), pp. 439-555 : 451-454

Genus Calocarides Wollebaek, 1909

TYPE SPECIES. — Euconaxius coronatus Trybom, 1904 , subsequent designation by Sakai & de Saint Laurent (1989).

DIAGNOSIS. — Rostrum slender, triangular, pointed at tip; margin carrying a row of teeth and continuous backward to lateral carina of gastric region. Anterolateral margin of carapace usually unarmed. Gastric region convex with one median and two submedian carinae; cervical groove present to whole length. Abdominal pleura rounded ventrally, lacking lateral tufts of setae. Telson subsquare or longer than wide, with slight dorsal carinae; posterior border convex bearing median spinule.

Eyestalk subglobose, pigmented or not; antennal acicle prominent, elongated. Mx2 scaphognathite bearing pair of long posterior setae. P1 unequal, P2 chelate, P3-5 simple.

Exopod on Mxp1-3; single epipods on Mxp1-3 and P1-4; single rudimentary podobranch on Mxp3 and P1-3; paired arthrobranch on Mxp3 and P1-4.

Male Plp1 absent, female Plp1 uniramous; male Plp2 slender, biramous, with appendix interna and appendix masculina, female Plp2 with appendix interna.

Uropodal exopod with transverse suture.

Calocarides coronatus ( Trybom, 1904) ( Figs 2 ; 3 )

Euconaxius coronatus Trybom, 1904: 384 , pl. 20 figs 1-10, 13, 14, pl. 21 figs 1-8.

Euconaxius crassipes Trybom, 1904: 390 , pl. 20 figs 11, 12.

? Axius (Neaxius) laevis Bouvier, 1915: 182 . — de Man 1925b: 13 (key).

Axiopsis (Calocarides) coronatus – de Man 1925b: 6, 67, 71 (key).

Axiopsis (Calocarides) crassipes – de Man 1925b: 6, 67, 71 (key).

Calocarides coronatus – Wollebaek 1909a: 3. — Balss 1925: 209; 1926: 26. — Grieg 1927: 43. — Poulsen 1941: 216, fig. 4. — Bouvier 1940: 97. — Christiansen 1955: 1; 1972: 40, fig. 45; 2000: 231. — * Elofsson 1959: 1, figs 1-20. — Brattegard 1966: 45, fig. 1, tabls 1, 2. — Allen 1967: 57 (key), 89 (fig.). — Sakai & de Saint Laurent 1989: 80, fig. 20. — Noël 1992: 79. — ° Cartes et al. 1994: 137. — ° García Raso 1996: 738. — Kensley 1996: 56. — ° Brattegard & Christiansen 1997: 220. — d’Udekem d’Acoz 1999: 153. — *González-Gordillo et al. 2001: 279. — ° Türkay 2001: 289.

Calocarides crassipes – Wollebaek 1909a: 23, pls 1-7.

TYPE MATERIAL. — Whereabouts unknown.

MATERIAL EXAMINED. — Norway. Nordfjord, 556- 578 m, T. Brattegard leg., 18. VI.1983, 2, 4

(1 ovig. cl. 13.5 mm, tl. 40 mm) ( SMF 11835).

North Sea. Skagerrak, N Skagen, 320 m, F. S. Alkor coll., 22.VII.1987, 1 ovig. cl. 17 mm, tl. 49 mm ( SMF 19774) ; S Arendal, 441-448 m, F. S. Valdivia , 25.II.1987, 1 damaged spec. ( SMF 25687) .

Sweden. W coast, Kosterfjord, Sv. Hydr. Kom. Expedition, 220-230 m, F. Trybom coll., 12.VIII.1901, 1 cl. 14 mm, tl. 43 mm (figured) ( SMNH 1186); about 230 m, 6.VII.1902, 1, 1 ( SMNH 1189). — Bohuslan, W of Hållö, 90 fms (162 m), B. Wingård coll., I.1939, 1 cl. 15.5 mm, tl. 49 mm (figured), 1 cl. 14.5 mm, tl. 44.5 mm (figured), 1 broken cl. 15 mm, tl. 46.5 mm ( SMNH 5221).

Mediterranean. Alboran Sea, BALGIM Exped., stn CP 127, 35°35.4’N, 3°48.5’W, 720 m, 18. VI.1984, 1 cl. 5 mm, tl. 14.5 mm (MNHN Th 1179). — Catalan Sea slope, 1 cl. 7 mm, tl. 18.5 mm.

DISTRIBUTION. — North Sea, Norway, Sweden, Denmark ( Poulsen 1941; Sakai & de Saint Laurent 1989). Mediterranean: Alboran Sea ( García Raso 1996), Catalan coast ( Cartes et al. 1994).

DIAGNOSIS

Rostrum ( Fig. 3C ) triangular, slender, pointed at tip, reaching beyond eye; lateral rostral margin continuous with lateral carina, together with 11- 13 spines, smaller distally. Eye nearly reaching middle of rostrum; eyestalk cylindrical, cornea distal, rounded, unpigmented. Gastric region weakly convex, cervical groove well defined; median carina with one or two spines near anterior border of gastric region, submedian carinae with two spines. Pleuron of abdominal somite 1 narrow, ventrally rounded; pleura of somites 2-5 ventrally rounded ( Fig. 3A ), all unarmed; thoracic sternite of P4 with minute spine. Telson ( Fig. 3B ) 1.3 times as long as proximal width, with denticles on lateral border, pair of slight dorsal carinae diverging distally, each with one or two spinules, posterior margin convex with median spinule.

A2 ( Fig. 2S ) acicle large, acute, reaching approximately distal margin of fourth article of peduncle. Md ( Fig. 3K ) cutting edge smooth. Mx1 ( Fig. 2M ) endopod with distal article sickle-shaped; Mx2 ( Fig. 2R ) scaphognathite bearing pair of long posterior setae. Mxp1 ( Fig. 3H ) endopod slender, exopod with two-articulate distal flagellum, epipod with truncate posterior lobe. Mxp2 ( Fig. 3I ) exopod with multiarticulate distal flagellum overreaching distal border of merus. Mxp3 ( Fig. 3J ) endopod with three to five lower distal spines on merus; exopod with multiarticulate distal flagellum.

P1 unequal in adult male, subequal in young male and female. Larger P1 of adult male ( Fig. 3D ) stout and spinous, with fingers about onethird as long as palm, dactylus well curved; smaller P1 of adult male ( Fig. 3E .) as well as both P1 of young male and female, more slender, laterally compressed, with fingers about as long as palm, dactylus slightly curved. All P1 with lower distal spine on ischium, two or three upper subdistal spines and one lower median spine on merus, upper spines and spinules on carpus, propodus and dactylus. P2 ( Fig. 3F ) chelate, with lower spine on ischium, one or two lower spines on merus. P3, P4 and P5 ( Fig. 3G ) simple.

Male Plp1 absent (with exception); male Plp2 ( Fig. 2P ) with appendix interna and appendix masculina; exopod and endopod slender. Female Plp1 ( Fig. 2N ) of one article, slender; female Plp2 ( Fig. 2O ) with appendix interna. Male and female Plp3-5 ( Fig. 2Q ) with appendix interna.

Uropod ( Fig. 3B ) endopod and exopod about as long as telson; endopod with spine on lateroposterior border and median carina bearing three or four spinules; a suture with spiniform setae near posterior border of exopod.

Colour

Body and pereopods pale dull brown, eyes brownish white, eggs dark brown (d’Udekem d’Acoz pers. comm.).

Size

Type material of tl. 21-52 mm ( Trybom 1904); adult males in present material of cl. 14-15.5 mm, tl. 43-49 mm; ovigerous females of cl. 13.5- 17 mm, tl. 40-49 mm. Largest size reported: tl. 57 mm ( Wollebaek 1909a; Christiansen 1955), tl. 53 mm ( Christiansen 1955). Specimens from the Mediterranean are smaller: cl. 5 mm and 7 mm, tl. 14.5 and 18.5 mm.

ECOLOGY AND BIOLOGY

The species lives in soft muddy bottom and deep waters, 162-578 m (present material), 440- 460 m in Denmark ( Poulsen 1941) or 400- 424 m in Norway ( Wollebaek 1909a).

An extensive study in Norvegian waters by Brattegard (1966) reveals that this species is a mud eater, living in a depth range of 225- 670 m. It is found together with Calocaris macandreae ; the latter dominates in shallow waters while C. coronatus does at depths of 500 m and below. C. coronatus has been collected in sediments of Md <7.6 µm, at temperatures of about 6-7.5°C and salinity of 35‰. Ovigerous females are record- ed from March to November, all from depths exceeding 340 m. Egg-laying occurs during February-March; the eggs are carried for about 10 months and hatch in November-December.

The larvae attributed to Calocarides coronatus and described by Elofsson (1959) were obtained from the Korstfjord (western Norway) over a muddy bottom, at 600 m depth. The development presumably includes at least three larval stages.

REMARKS

This deep water species is likely to be distributed from the north of Europe to the Mediterranean although it has not been reported from the British Isles or the European Atlantic coast so far. The specimens studied by Cartes et al. (1994) and García Raso (1996), though smaller, agree well with those from the north. Cartes (pers. comm.) also stated that C. coronatus was regularly found in Mediterranean waters, always at bathyal depths.

In most of the material examined, Plp1 are absent in males as always previously reported. One exception nevertheless exists and small Plp1 are present in one specimen figured here ( Fig. 3A ).

There is uncertainty about the synonymy of Axius (Neaxius) laevis Bouvier, 1915 with Calocarides coronatus as proposed by Sakai & de Saint Laurent (1989: 82). The holotype and only known specimen of the former species is a young female in poor condition, of 20 mm in total length, with a broken rostrum and collected off the Moroccan coast (25°29’N, 18°18’W). It was partly figured ( Sakai & de Saint Laurent 1989: fig. 21) but unfortunately is now missing in the MNHN collection. Sakai & de Saint Laurent (1989) stated that “Bouvier’s species laevis is to be included in coronatus because the dorsal region of the carapace and the abdomen are identical with those of coronatus ”. Yet the original description ( Bouvier 1915: 182, 183) and Sakai & de Saint Laurent’s figure (1989: fig. 21A-D) show several differences: 1) in A2 peduncle of Axius laevis , the upper distal spine of the second article reaches the middle of the antennal acicle (in C. coronatus , the same upper distal spine reaches one-third of the antennal acicle); 2) in A. laevis , the A2 acicle is two-thirds as long as the fourth article, the latter terminating approximately at the level of the A1 peduncle ( Sakai & de Saint Laurent 1989: fig. 21B) (in C. coronatus , the A2 acicle is about as long or slightly longer than the fourth article, the latter far overreaching the A1 peduncle, Figs 2S ; 3C ); 3) in the original description or figure by Sakai & de Saint Laurent, there is no mention of submedian carinae and spines (these are present in C. coronatus , Fig. 3C ); and 4) the telson is over 1.5 times as long as wide, with four or five spinules on the lateral border, the subdistal one largest in A. laevis (telson 1.3 times as long as wide in C. coronatus , with no spinule on the lateral border, Fig. 3B ).

Also doubtful is the assignement to Calocarides coronatus (“by geographical reason”, Sakai & de Saint Laurent 1989: 79) of materials previously identified as Calocarides longispinis (McArdle, 1901) by Stebbing (1910: 367), Barnard (1950: 503, fig. 93d-f), Kensley (1981: 30), and two males in the MNHN collection. The three former materials were from South Africa while the MNHN specimens ( MNHN Th 1044 and 1045) were collected off Namibia (26°26’S, 14°25’E and 20°1’S, 11°38’E respectively). The latter are very similar to specimens of C. coronatus but differ in: 1) their larger size, tl. 72.5 mm and 73 mm; 2) both P1 are laterally compressed, with upper and lower longitudinal rows of spines and spinules on merus, numerous tubercles on lateral surface; 3) larger P1 with fingers over two-thirds as long as the palm, dactylus nearly straight; and 4) large acute spines along the carinae of the telson and uropodal endopod.

Figures

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.

FIG. 3. — Calocarides coronatus (Trybom, 1904); A-F, from Kosterfjord, Sweden (SMNH 1186); G-K, from Bohuslan, Sweden (SMNH 5221); A, lateral view, pereopod 1 and 5 omitted; B, telson and uropods; C, anterior part of carapace; D, E, right and left pereopod 1; F, G, pereopod 2 and distal part of pereopod 5; H-J, maxilliped 1-3; K, mandible. Scale bars: 2 mm.