Numerous samples of Stylodactylidae collected between 1976 and 1989 off the Philippines, New Caledonia and Chesterfield Islands (MUSORSTOM, BIOCAL, CHALCAL, CORAIL 2 and SMIB cruises) are studied here. Other collections from Indonesia (CORINDON 2 cruise), Madagascar (coll. A. CROSNIER and R. CLEVA), and la Réunion («MARION DUFRESNE»,cruise MD 32) are included. This material is of particular interest since many specimens of various taxa have been collected: eighteen species and subspecies have been identified in it, of which nine are new: three species and one subspecies in the genus Stylodactylus, four species in the genus Parasty-lodactylus, and one in the new genus Stylodactyloides. Nine species and one subspecies of the genus Stylodactylus A. Milne Edwards, 1881, are represented in the collections studied here. S. laurentae sp. nov., with its typically short rostrum, seems to be one of the most common shrimps of the genus in New Caledonia and Chesterfield Islands. S. profundus sp. nov., unfortunately represented by specimens in incomplete or poor condition, extends the bathymetric range of the family: it has been collected, off New Caledonia, between 1395-1410 and 1618-1740 m. S. brevidactylus sp. nov. is represented by a single specimen from the Philippines: we at first considered that this specimen was an aberrant example of S. multidentatus Kubo, 1942, but decided then to re-examine our opinion because of its peculiar characters. Twenty seven specimens (eleven from the Philippines and sixteen from Chesterfield Islands and New Caledonia) have been identified as S. licinus Chace, 1983, a little known species described from the Philippines, and eleven others (one from Indonesia and ten from New Caledonia and Chesterfield Islands) as S. tokarensis Zarenkov, 1968, only known by the holotype collected in the east China sea (the para type of S. tokarensis is suspected of being a specimen of S. licinus Chace). S. multidentatus Kubo, 1942, is probably one of the most commonly caught species of the family. Many specimens have been collected by the french campaigns from the Philippines, New Caledonia, and Madagascar: Neocaledonian specimens differ from the former by a longer rostrum and longer spines on the margin of the antennal scale. These differences are still more accentuated in Madagascarian specimens, and we finally decided to create for them a new subspecies, S. multidentatus robustus. Two other species of Stylodactylus are represented in our material: S. macropus Chace, 1983, of which the only previouly known specimen was collected by the «ALBATROSS» in the Philippines, is reported here, again from the Philippines and from New Caledonia and Chesterfield Islands. S. libratus Chace, 1983, described from a single specimen from Indonesia (Celebes, «ALBATROSS» collection) and reported then from Australia (New South Wales) by KENSLEY, TRANTER and GRIFFIN (1987) has been collected in New Caledonia and Chesterfield Islands. One specimen from Madagascar appears to be very close to S. Libratus but shows however some differences from it, so that we identify it as S. aff. libratus. The genus Neostylodactylus Hayashi & Miyake, 1968 is presented in our material by two species: N. amarynthis (de Man, 1902), and N. affinis Hayashi & Miyake, 1968: in these two species we have noted particular sexual dimorphism mentioned by CHACE (1983: 6) for N. amarynthis: females differ from males in lacking arthrobranchs on pereiopods 1 to 4. The geographical distribution of N. amarynthis now, in the Indo-Pacific, to the southwestern Indian Ocean (La Réunion), and that of N. affinis, previously known only from the Korea Strait at 120 m depth, is shown to belong to the New Caledonia and Chesterfield Islands fauna; it has been caught between 235 and 440 m. Four new species have been included in the genus Parastylodactylus created by FIGUEIRA in 1971 for Stylodactylus bimaxillaris Bate, 1888, and until now monospecific. P. bimaxillaris (Bate), known from a large part of the Indo-Pacific, is mentioned for the first time from New Caledonia and Madagascar. P. tranterae sp. nov., collected off New Caledonia and Chesterfield Islands, was first reported from Australia (New South Wales) by KENSLEY, TRANTER and GRIFFIN (1987) who suspected that it was a new species, but did not name it, on account of the poor condition of the single specimen in their possession. P. semblatae sp. nov. seems to be very common in New Caledonia and Chesterfield Islands. P. richeri sp. nov., from New Caledonia, and P. longidactylus sp. nov., from the Philippines, each represented by a few specimens only, are fairly closely related species, but however are clearly distinct taxa. A new genus, Stylodactyloides, is proposed for a new species collected from New Caledonia and Chesterfield Islands, S. crosnieri, which has a very unusual stylocerite, broadly rounded distally, which distinguishes it from all other members of the family. It may be noted that several points in the systematics of the Stylodactylidae remain obscure. These will necessitate the examination of new collections. This work, however, shows the particular interest of these collection, concerning a little known and poorly represented family (nine new taxa described, representing more than one third of the species known until now), and indicates the richness of New Caledonia and Chesterfield Islands waters, where thirteen species have been collected, including six of the nine new ones. All the new taxa have been illustrated, and individual variations carefully studied in the species represented by numerous specimens. Color photographs of several species, taken on board during some of these cruises, complete the iconography. Identification keys are proposed for the four genera and twenty six species and subspecies now recognized in the family. |
