Morphological changes during the transition from freshwater to sea water in an amphidromous goby, Sicyopterus lagocephalus (Pallas 1770) (Teleostei).

TitreMorphological changes during the transition from freshwater to sea water in an amphidromous goby, Sicyopterus lagocephalus (Pallas 1770) (Teleostei).
Type de publicationJournal Article
Year of Publication2016
AuteursEllien, C, Werner, U, Keith, P
JournalEcology of Freshwater fish
Volume25
Pagination48-59
Mots-clésamphidromy, larval development, larval morphology, Reunion Island, Sicyopterus lagocephalus
Résumé

The widely distributed amphidromous goby Sicyopterus lagocephalus needs drastic change of habitat to

fulfil its life cycle: adults live and spawn in rivers, where eggs hatch into prolarvae that have to reach the sea to

acquire characteristics of planktonic larvae. Postlarvae return to rivers where they recruit and grow to the adult

reproductive stage. Here, we describe the prolarval stages, namely from hatching to first contact with sea water, as

well as the first marine larval stages. The observations were made under experimental conditions. We described 3

prolarval substages in freshwater (L1a–L1c). Prolarvae present a slight but visible ontogenetic development in

freshwater, during which the yolk sac begins to reduce, the pigmentation increases on the body and in the eyes, and

the lenses appear, although the eyes are not functional. Prolarvae need to reach the sea in a maximum of 96 h to

pursue their development. Their transfer in sea water at a salinity of 36.5 induces important morphological

modifications (i.e. yolk sac full absorption, appearance of pectoral fins, migration of the eyes in anterolateral

position of the head, opening of mouth and anus), enabling the organisms to adapt to their new environment. This

marine stage is divided into two substages: L2a corresponding to the organisation of the morphological structures

adapted to the marine environment and L2b during which these morphological structures become functional.

Whether it is in freshwater or sea water, the duration of the substages depends on the water temperature, but is

similar for all individuals for a given temperature.

Catégorie HCERES
ACL - Articles dans des revues à comité de lecture
Publication coopération et recherche SUD
Non