An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from Snappers and Bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish

Abstract

BackgroundCoral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific.ResultsHost-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size > 30), the number of host-parasite combinations is 20–25 per fish species, and the number of parasites identified at the species level is 9–13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species.ConclusionsSince all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites.

The molecular phylogeny of the digenean family Opecoelidae Ozaki, 1925 and the value of morphological characters, with the erection of a new subfamily

“…in the excretory vesicle, which reaches to the posterior edge of the ventral sucker (Yamaguti 1952, Bray andCribb 1989), but not into the forebody as is characteristic of Hamacreadium. Hamacreadium mutabile is a widely reported parasite mainly of lutjanid fishes, and our worms from New Caledonia have been identified as this species (Justine et al 2012). Morphologically it is similar to the Gulf of Mexico form, but molecular evidence from lsrDNA suggests that H. 'mutabile' and H. mutabile are as distinct from each other, as Hamacreadium sp.…”

Monogenean parasites of sardines in Lake Tanganyika: diversity, origin and intraspecific variability

“…Most recent taxonomic studies focused on monogeneans infecting cichlids in the species-rich littoral zone (see overview in Kmentová et al, 2016). Interestingly, while a high host-specificity was observed in monogeneans infecting cichlids in Lake Tanganyika's littoral zone , the observed lower level of host-specificity reported on bathypelagic cichlids of the tribe Bathybatini Kmentová et al, 2016) resembles the situation in pelagic and deep water marine environments (Dogiel and Bogolepova, 1957;Rohde, 1980;Justine et al, 2012;Schoelinck et al, 2012). This phenomenon has been explained by lower host species densities and increased home range compared to the littoral habitat and hence a decreasing speciation rate of parasites (Rohde, 1988).…”

Diversity of trypanorhynch metacestodes in teleost fishes from coral reefs off eastern Australia and New Caledonia

“…[ 33 ]) or Digenea (e.g. [ 13 ]), or more recently have examined the diversity of all helminth parasites found in or on specific families of fish such as the Lethrinidae or Serranidae [ 21 – 23 ].…”