Doridicola helmuti, Conradi & Bandera & López-González, 2006

Conradi, Mercedes, Bandera, M Eugenia & López-González, Pablo J., 2006, The copepods associated with the coral Astroides calycularis (Scleractinia, Dendrophyllidae) in the Strait of Gibraltar, Journal of Natural History 40 (13 - 14), pp. 739-757 : 740-747

Doridicola helmuti sp. nov.

( Figures 1–5)

Material examined

MNCN 20.04/7575 holotype, one adult female, associated with the scleractinian Astroides calycularis, Tarifa Island , 36 u 019N, 5 u 379W, 25–30 m depth, July 1999 ; MNCN 20.04/ 7576 allotype, adult male, with the same sampling data as the holotype; MNCN 20.04/ 7577 paratypes, 10 females and seven males, with the same sampling data as the holotype; BEIM ( COP 215 ), 10 adult females, six adult males and 12 copepodids, with the same sampling data as the type material; BEIM ( COP 216 ), three adult females, and four copepodids, associated with the scleractinian Astroides calycularis, Punta Desnarigado , Ceuta, North Africa , 35 u 539N, 5 u 189W, 40 m depth, August 1998 ; BEIM ( COP 217 ), three adult females and five adult males, associated with the scleractinian Astroides calycularis, Tarifa Island , 36 u 019N, 5 u 379W, 25 m depth, October 1999 .

Description Female. Body ( Figure 1A) 985 Mm long (920–1008 Mm) (excluding setae on caudal rami)

and 362 Mm wide (340–400 Mm) (greatest width of cephalothorax) based on six females in lactic acid. First pediger separated from cephalosome by distinct dorsal furrow. Ratio of length to width of prosome 1.7:1. Ratio of length of prosome to that of urosome 1.62:1. Segment bearing leg 5 subquadrate, 57.7692.9 Mm. Genital double somite ( Figure 1A, B) 1.23 times longer than wide, 134.66109 Mm, with prominent anterodorsal bulge expanding laterally to egg sac attachment area and overhanging narrow posterior part of somite proper ( Figure 1A, B). Genital areas composed of two parts, the first one rounded with short plumose seta and two spiniform processes. Second part subquadrate bearing a longer plumose seta and a small spiniform process ( Figures 1C, 5B ).Three free abdominal somites 60657.7, 43.3648, and 57652.9 Mm, respectively ( Figure 1A, B). Posterodorsal border of genital segment and of the two first postgenital segments irregular. Caudal ramus ( Figure 1A, B) 3.4 times longer than wide, measuring 81.7624 Mm and bearing six setae in terminal area. Outer lateral seta 38.4 Mm, dorsal seta 80 Mm, both smooth. Outermost terminal seta 89.7 Mm, innermost terminal seta 102. 5 Mm, both with lateral setules widely spaced. The two median terminal fringed setae 221 Mm (outer), 214 Mm (inner) with setules on their outer margin. Egg sac elongate, oval. Dorsal surface of body lacking visible ornamentation, except for minute setules as shown in Figure 1A.

Rostrum broadly rounded posteroventrally. Antennule ( Figure 1D) seven-segmented, with armature formula: 4, 13, 6, 3, 4+1 aesthete, 2+1 aesthetasc, and 7+1 aesthetasc. Antenna ( Figure 1E) four-segmented; with formula of armature: 1, 1, 3, and 3+2 subequal claws slightly dentate ( Figure 5C ). Claws 2.5 times longer than the last segment. Labrum with two large, divergent posteroventral lobes. Mandible ( Figure 2A ) minute, with shallow proximal notch followed by a short terminal lash setulose on its outer side. A small lobe bearing three to four teeth between the proximal notch and the lash. Convex margin with a naked outer scale. Maxillule ( Figure 2B ) armed with two terminal subequal setae, the inner plumose, and one spiniform process. Maxilla ( Figure 2C ) two-segmented; proximal segment (syncoxa) unarmed; distal segment (basis) ornamented with three typical setae: a tiny outer setula (seta III) at base, naked seta (seta II) on anterior surface, and seta armed with strong spinules (seta I) proximal to the base of the main lash and as long as it. Terminal lash armed along one side with large strong spinules. Maxilliped ( Figure 2D, E ) two-segmented; proximal segment unarmed; distal segment long with just one naked long seta which usually is around the segment, terminating in various barbed pointed processes and carrying a spiniform process with setules at its inner margin.

Legs 1–4 ( Figure 3A–D ) biramous, with three-segmented rami except the endopod of leg 4, which is two-segmented. Intercoxal sclerite present in legs 1–4. Formula of spines (in Roman numerals) and setae (in Arabic numerals) as follows:

Inner coxal seta plumose in all legs on inner margin of basis of all legs ornamented with setules and basal seta of all legs plumose.

Leg 5 ( Figure 1A, B) long, reaching more than half the length of the double genital segment and armed with small spinules; without proximal inner expansion. Two terminal smooth setae, subequal in length.

Male. Body ( Figure 4A ) 800 Mm long (760–830 Mm) (excluding setae on caudal rami) based on four males in lactic acid, with six-segmented urosome. Genital somite ( Figure 4A, B ) slightly wider than long. Four postgenital segments. Caudal ramus 2.3 times longer than wide with the usual six setae in terminal area as described for the female. Rostrum as in female. First antenna similar to that of female but with three aesthetascs at locations indicated by dots in Figure 1D. Second antenna slightly different from female in having spinules on the surface of the first and second segments. Labrum, mandible, maxillule, and maxilla resembling those of female. Maxilliped ( Figure 4C ) four-segmented; first segment (syncoxa) large but unarmed; second segment (basis) armed with a row of spinules and two inner setae, one of them inserted in a protuberance; third segment (endopod) smallest and unarmed; terminal claw as long as the preceding segments. The claw with terminal lamellae, one long barbed seta and a smaller naked seta at the basal region. Armature on rami of legs 1–4 are as in female, except for the armature of the endopod of leg 1 ( Figures 4D , 5A ) since the second lateral spine of the last segment has an additional spinule at its base. The free segment of leg 5 ( Figure 4A, B ) small, 21.768.6 Mm, tipped with two subequal setae. Leg 6 ( Figure 4B ) composed of two ventral subequal setae located at posterolateral corner of genital somite.

Etymology

The specific name helmuti is after Dr Helmut Zibrowius (Station Marine d’Endoume, Marseille) for his important contribution to our knowledge of the biodiversity and distribution of European scleractinians.

Remarks

Among the 46 species currently recognized in the genus Doridicola , 25 species have the two terminal claws of the antenna subequal in size like D. helmuti ( Ho and Kim 2001) , although none of them has the claw 2.5 times longer than the fourth segment. Furthermore, among these 25 species, only D. antheliae ( Humes and Stock, 1973) , associated with an actiniarian from Madagascar, and D. rostripes Humes, 1990 , living in an octocoral from the Moluccas, have a naked outer scale of the mandible. However, D. antheliae can be easily separated from the new species by: (1) the shape of the mandible; (2) the armature of the maxillule; (3) the seta I and II of the maxilla; and (4) the armature of the maxilliped and leg 5. The mandible of D. anthelinae has the concave margin deeply indented and, in general appearance, is stronger than in the new species. The maxillule has four elements in D. anthelinae and three in D. helmuti . The seta I of the maxilla is short, not reaching the terminal lash, and has spinules on both sides in D. anthelinae , while the new species has a long spined internal seta I. The seta II of this appendage is barbed in D. anthelinae and smooth in D. helmuti . The maxilliped has a very different armature in both species and D. anthelinae has an inner expansion on leg 5 which lacks spinules ( Humes and Stock 1973).

Doridicola rostripes differs from the new species by its broad flattened prosome, the robust second antenna, the three terminal seta of the maxillule, the slender maxilla, the armature of the maxilliped and the prominint beak-like process of leg 5 ( Humes 1990).

Therefore, the new species is easily separated from its congeners by the combination of the following features: (1) ratio of length of claw to that of the last segment of the second antenna; (2) armature of the inner margin of the mandible; (3) armature of the maxillule and the maxilliped; (4) the seta II of the maxilla; and (5) basal swelling of leg 5. Furthermore, the description of this new Doridicola species is the first record of this genus associated with a scleractinian coral.

Figures

Figure 2. Doridicola helmuti, female. (A) Mandible; (B) maxillule; (C) maxilla; (D) maxilliped, latero-posterior view; (E) maxilliped, latero-anterior view.

Figure 3. Doridicola helmuti, female. (A) Leg 1; (B) leg 2; (C) leg 3; (D) leg 4.

Figure 4. Doridicola helmuti, male. (A) Dorsal view; (B) urosome, dorsal view; (C) maxilliped; (D) endopod of leg 1.

Figure 5. Doridicola helmuti. (A) Male, detail showing (arrow) additional spinule on the second lateral spine of endopod dorsal view; (B) female, genital area; (C) female, detail of terminal claw of antenna.