Digenean metacercariae of fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific

Abstract

Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed in the Eastern Indo-Pacific (EIP) marine ecoregion, only a few have considered metacercarial stages. Here, the results are presented of a taxonomic survey of the digenean metacercariae of fishes from Palmyra Atoll, a remote and relatively pristine US National Wildlife Refuge located 1680 km SSW of Hawaii. Up to 425 individual fish were collected, comprising 42 fish species, from the sand flats bordering the lagoon of the atoll. Quantitative parasitological examinations of each fish were performed. Morphological descriptions of the encountered digenean metacercariae are provided, together with their prevalence, mean intensities, host and tissue-use. Up to 33,964 individuals were recovered representing 19 digenean metacercaria species from eight families. The species composition of digeneans in lagoon fishes at Palmyra Atoll is a subset of what has previously been reported for the EIP. Further, the large diversity and abundance of metacercariae reported in this study highlight the utility of including this group in future ecological research in the EIP marine ecoregion.

Parasitic nematodes of marine fishes from Palmyra Atoll, East Indo-Pacific, including a new species of Spinitectus (Nematoda, Cystidicolidae)

“…In the present study we have an opposite pattern where the lack of removal of the definitive hosts is the most likely explanation for the high number of larval nematodes using fishes as second intermediate hosts. We observed a similar pattern of abundant larval metacercarial stages in fishes at Palmyra (Vidal-Martínez et al 2012).…”

“…This study is part of a larger project to understand the structure and function of the Palmyra Atoll’s food webs. This paper is a companion to three others examining different fish parasite taxa (Vidal-Martínez et al 2012, 2017; Soler-Jiménez et al 2019) from Palmyra’s lagoon flats. As such, our survey adds to the few published, detailed species descriptions or host records from this Central Indo-Pacific region (Palm and Bray 2014).…”

Parasitic copepods (Crustacea, Hexanauplia) on fishes from the lagoon flats of Palmyra Atoll, Central Pacific

“…As part of a larger project assembling food webs at Palmyra Atoll, we have been cataloging the parasites found in the system. This paper is a companion to two others examining different fish parasite taxa (Vidal-Martínez et al 2012, 2017). We recovered a considerable number of parasitic copepods from 44 fish species.…”

Non-target species mortality and the measurement of brodifacoum rodenticide residues after a rat (Rattus rattus) eradication on Palmyra Atoll, tropical Pacific

“…All 21 groups of dead mullet that we collected contained detectable brodifacoum residues. Mullet range widely in the Palmyra lagoon environment and are fed upon by a wide variety of predatory fish (e.g., bluefin trevally (Caranx melampygus) and giant trevally (C. ignobilis), blacktip reef sharks (Carcharhinus melanopterus), and barracuda (Sphyraena barracuda)), and potentially seabirds, such as brown noddies (Anous stolidus) (Ashmole, 1967;Vidal-Martínez et al, 2012;J. McLaughlin unpubl.…”