Anguilliform fishes and sea kraits: neglected predators in coral-reef ecosystems

Abstract

International audienceDespite intensive sampling eVorts in coral reefs, densities and species richness of anguilliform Wshes (eels) are diYcult to quantify because these Wshes evade classical sampling methods such as underwater visual census and rotenone poisoning. An alternative method revealed that in New Caledonia, eels are far more abundant and diverse than previously suspected. We analysed the stomach contents of two species of sea snakes that feed on eels (Laticauda laticaudata and L. saintgironsi). This technique is feasible because the snakes return to land to digest their prey, and (since they swallow their prey whole) undigested food items are identiWable. The snakes' diet consisted almost entirely (99.6%) of eels and included 14 species previously unrecorded from the area. Very large populations of snakes occur in the study area (e.g. at least 1,500 individuals on a small coral islet). The snakes capture approximately 36,000 eels (972 kg) per year, suggesting that eels and snakes play key roles in the functioning of this reef ecosystem

A rare species of Uropterygius (Anguilliformes, Muraenidae) found in the stomach content of a Yellow-lipped Sea Krait from Japan

“…In addition to U. xenodontus reported here, other poorly known fish species have been found in recent investigations of sea krait stomach contents (Tabata et al 2017). As evident here and also suggested by Ineich et al (2007) and Séret et al (2008), examination of the stomach contents of sea kraits provides an additional useful tool for investigating the diversity of tropical and subtropical fishes. …”

“…have a key role as predators of coastal fishes in tropical and subtropical regions. Some species specialize on feeding of anguilliform fishes, despite a large variety of co-existing fishes (McCosker 1975, Ineich et al 2007, Tabata et al 2017. When studying the stomach contents of Laticauda spp.…”

Ecology of Anguilliform Leptocephali: Remarkable Transparent Fish Larvae of the Ocean Surface Layer

“…Seabirds were observed feeding their young large leptocephali off the coast of Brazil (Figueroa 1997), and "eels and eel larvae" were reported as being among the gut contents of dolphin fish (Coryphaena hippurus) collected east of Taiwan during winter (Wu et al 2006); but the latter case appears to be unusual compared to other studies of the food habits of dolphin fish. Some types of sea snakes are known to target small moray eels as prey (Reed et al 2002;Ineich et al 2007;Brischoux et al 2009), and marine mammals such as dolphins sometimes feed on eels when they are abundant (Amir et al 2005), but there is apparently no predator that is known to feed regularly on leptocephali.…”

Phylogenetic relationships of Gymnothorax bacalladoi Böhlke and Brito (1987) a poorly known moray of the Macaronesian islands

“…Moray eels, in spite of their diversity, presence in all tropical and temperate oceans (Nelson, 2006) and their role as major predators in reef ecosystems (Thresher, 1984;Ineich et al, 2007) have been poorly studied from a phylogenetic perspective, with obvious consequences for their taxonomy. Northeastern Atlantic morays belong to several genera namely Muraena, Gymnothorax, Enchelycore and Anarchias, which are also present in the Indian and Pacific oceans (Froese and Pauly, 2008) an observation that raises the possibility that the morays of the Lusitanian province may belong to lineages which diverged before the closure of the Tethys Sea.…”