Insights on endemism: comparison of the duration of the marine larval phase estimated by otolith microstructural analysis of three amphidromous Sicyopterus species (Gobioidei: Sicydiinae) from Vanuatu and New Caledonia

Abstract

Lord C, Brun C, Hautecœur M, Keith P. Insights on endemism: comparison of the duration of the marine larval phase estimated by otolith microstructural analysis of three amphidromous Sicyopterus species (Gobioidei: Sicydiinae) from Vanuatu and New Caledonia. Ecology of Freshwater Fish 2010: 19: 26–38. © 2009 John Wiley & Sons A/S Abstract – The microstructure of otoliths of three amphidromous gobies (Sicydiinae) of the genus Sicyopterus has been analysed. One of these species, Sicyopterus lagocephalus has a widespread distribution whereas the other two are endemic (Sicyopterus aiensis, from Vanuatu and Sicyopterus sarasini, from New Caledonia). The microstructural analysis of the otoliths showed that the duration of the marine larval phase is significantly shorter for both endemic species than for the cosmopolitan species (131 ± 3.4 days for S. lagocephalus, 79.2 ± 4.6 days for S. aiensis and 76.5 ± 3.9 days for S. sarasini). These results led us to infer that it could be one of the factors explaining endemism. We have also improved our knowledge on the processes undergone during the marine phase by studying the growth of the otolith. This work allowed us to propose possible migration routes. These species’ reproduction period has also been studied by back‐calculating hatching dates. All these elements improve our understanding of the life‐history traits and dispersion strategies of these species, which is crucial to implementing conservation measures in order to protect them and their environment, both threatened by anthropogenic actions.

DNA Barcoding Indonesian freshwater fishes: challenges and prospects

“…Past connectivity among islands, however, had different consequences for those lineages. This trend is particularly evident for amphidromous species with marine larval stages enabling connectivity among populations from different islands and exhibiting highest colonization potential due to their ability to achieve largescale dispersal as a consequence of long larval survival in oceans [97,98]. As a consequence, such amphidromous lineages show more similarity in their population dynamic with coastal marine fishes whose adults are sedentary and connectivity is maintained through larval dispersal as observed in coral reef fishes [99][100][101].…”

Stiphodon melen. sp., a new species of Freshwater goby from Vanuatu and New Caledonia (Teleostei, Gobiidae, Sicydiinae), and comments about amphidromy and regional dispersion

“…It seems that post-larvae are drawn to fresh water flowing into the sea along coastal zones. With their sucker, they can climb waterfalls and therefore colonise high elevation streams (Lord et al, 2010). This species is widespread in the IndoPacific area; it occurs in the Western Indian Ocean, from the Comoros Islands to the Mascarenes, and in the Pacific, in New Caledonia and Vanuatu, as far as French Polynesia and Japan.…”

“…This species is widespread in the IndoPacific area; it occurs in the Western Indian Ocean, from the Comoros Islands to the Mascarenes, and in the Pacific, in New Caledonia and Vanuatu, as far as French Polynesia and Japan. Sicyopterus lagocephalus is an indicator of good water quality (Lord et al, 2010) and is listed 'Least concerned' by the IUCN on the red list of threatened species.…”

“…Additional inventories were completed between 2004 and 2010 , particularly in Mt. Panié region, Côte oubliée and Bélep Islands (Keith et al, 2009b;Keith et al, 2010). Many new species were found during surveys carried out over the last decade (see Marquet et al, 2003;Keith et al, 2009;Keith et al, 2010a).…”

“…Amphidromous species: females spawn many ova in freshwater, which are then fertilised by the males. After hatching the larvae are carried by the current out to sea where they spend a variable amount of time (Valade et al, 2009;Lord et al, 2010;Taillebois et al, 2012). The young fry then go back to freshwater to resume their growth (Keith et al, 2008).…”