What are the decapod crustacea known from French Polynesia? The answer to this, apparently simple question, would be very helpful for determinating the species collected during ecological studies. Moreover, from a biogeographical point of view, a check list of the species reaching this area, at the eastern limit of the Indo-West Pacific province, would be very interesting.
Jonathan Sauer (1961) remarked, in his Coastal Plant Geography of Mauritius, that the chance to study the coastal vegetation there was like being "admitted to a field worker's paradise"
and stressed that "most tropical coasts are beautiful and exciting, particularly to people concerned with natural processes . . .." The same can certainly be said for the tropical coasts of the often Edenized islands of the Pacific Ocean. Their "beauty and excitement" is considerably enhanced,
This paper describes the channels known as hoa which are characteristic of atoll land rims and of some islands on barrier reefs, where they often dissect previously more continuous reef-top sediment accumulations and conglomerate platforms. They are
The colonization of the lagoon by coral reef fish larvae was compared between two islands of French Polynesia, the atoll of Rangiroa and the high volcanic island of Moorea. In both cases the larval flux coming into the lagoon followed a daily cycle.
Coral atolls are natural laboratories within which to examine ecological processes (Sachet, 1967; Lee, 1984). They are often isolated, in some cases little disturbed, and have a geologically recent history of terrestrial plant colonisation. Reef islands around the rim of most atolls are Holocene in age. They are composed of biogenic skeletal sediments and have developed since reef growth caught up with sea level which stabilized after post-glacial sea-level rise. Plant colonisation of most of these islands must have occurred over a period of no more than 6000 years.
In a typical High Island coral reef complex of French Polynesia (transect of Tiahura, Hoorea Island, Society Archipelago!, 73 species of decapod Reptantia and stomatopod crustaceans were collected. Over 9 stations localised along the transect, 3 different units of hard coral substrate of simi1ar volume (about 17 litres each), were sampled at each station. The results are discussed from two aspects : the first shows that at least 50 carcinologic species occur within the cavitary biotopes ; 16 species (mainly Xanthid crabs), represent more than 90% of all collected individuals.
During the period February 13 to 20, 1973, a visit was made to Canton Island for the purpose of conducting a preliminary survey of marine turtle nesting populations. Although previous investigators have described the sea birds (Buddle, 1938; Murphy G., 1954), insects (Van Zwaluwenburg, 1943, 1955), and vegetation (Hatheway, 1955), very little is known about the marine environment of Canton or the other seven atolls (Enderbury, Birnie, Phoenix, Sydney, Hull, Gardner and McKean) which comprise the Phoenix group.
Nukutipipi atoll (5 km2), of volcanic origin 16-17 million years old on the Pitcairn (hot spot) Hereheretue line, presents a land flora and fauna of low diversity but with a Pisonia forest and hundreds of resident red-tailed tropic birds. Nukutipipi suffered from the 1983 hurricanes : destruction of vegetation and motu as well as sand lagoon mollusc populations. The north and south rims present original geomorphological structures.
The shorefishes of Ouvea, an isolated atoll in the Loyalty Islands group of New Caledonia, had not been surveyed prior to 1990. An extensive survey was conducted by ORSTOM between 1991 and 1992 to obtain baseline information on the shorefishes. A
total of 653 taxa among 72 families are now documented from this area. The most diverse families are the Labridae (69 species), Pomacentridae (58 species), Gobiidae (54 spccies),Serranidae (39 species), Chaetodontidae (31 species) and Apogonidae (28