@article {4584, title = {Specific gravity and migratory patterns of amphidromous gobioid fish from Okinawa Island, Japan}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {486}, year = {2017}, pages = {160-169}, abstract = {

Amphidromy is a diadromous life history pattern where fish spawn in freshwater, and their larvae drift downstream to the sea; the larvae develop in marine environments then migrate back in rivers to grow and reproduce. Two amphidromous types with different life history characteristics, such as egg and larval sizes, exist. To understand the ecology and early life history of amphidromous gobioid fish, six species from Okinawa Island were selected{\textemdash}two large egg-type species (Rhinogobius similis and Tridentiger kuroiwae) and four small egg-type species (Stiphodon percnopterygionus, Stenogobius sp., Sicyopterus lagocephalus, and Eleotris acanthopoma). The migratory pattern of four of these species was confirmed using otolith Sr:Ca and Ba:Ca ratios combined with water chemistry analysis. Although these species showed amphidromous migratory patterns, the timing of migration from estuarine to freshwater habitats was species-specific. The large egg-type, R. similis, showed three different migratory patterns: a long marine larval phase with a relatively fast migration from estuarine to freshwater habitats, a short marine larval phase with a relatively fast migration, and a gradual migration. Similar patterns of a long and fast migration or a gradual migration were seen in T. kuroiwae; however, the two small eggtype species, Sti. percnopterygionus and Stenogobius sp., showed rapid migration to freshwater after entering the river. To estimate larval ecology in the sea, ontogenetic changes in specific gravity (SG) were examined in all species. The SG was measured day and night for 1{\textendash}5 days until settlement in R. similis and T. kuroiwae, and until 10 days after hatching in the other species. The SG of all species ranged from 1.0138 to 1.0488, and varied among ontogenetic stages and between day and night and species. Larval SG was relatively similar between R. similis and T. kuroiwae, with low SG in the early stages and high SG after yolk absorption. During the late larval stages and until settlement, T. kuroiwae showed diel changes in SG, with higher SG during the day, whereas R. similis had a relatively constant pattern. The diel changes of T. kuroiwae larvae suggest different activity during the day and at night (e.g. diel vertical migration). In the four small egg-type species, SG was high at hatching and decreased thereafter, not showing large diel changes. The results suggest that sympatric amphidromous gobioid species have various early life histories that may be influenced by several larval traits, including SG.

}, keywords = {Buoyancy, diadromy, Early life history, Migratory history, otolith, Specific gravity}, author = {Iida, Midori and Masashi Kondo and H{\'e}l{\`e}ne Tabouret and Maeda, Ken and P{\'e}cheyran, C and Atsushi Hagiwara and Philippe Keith and Katsunori Tachihara} } @article {3722, title = {Amphidromy and marine larval phase of ancestral Gobioids Rhyacichthys guilberti and Protogobius attiti (Teleostei: Rhyacichthyidae).}, journal = {Marine and Freshwater Research}, volume = {65}, year = {2014}, pages = {776{\textendash}783}, abstract = {

Even if amphidromous fish species contribute most to the diversity of fish communities in the tropical insular
rivers, their biological cycle remain poorly known. For the first time, the otolith elemental composition and microstructure
of two ancestral gobioids, Rhyacichthys guilberti and Protogobius attiti, were investigated to describe their biological
cycle and pelagic larval duration (PLD). The otolith analysis using a femtosecond laser ablation coupled to an inductively
coupled plasma{\textendash}mass spectrometer (fs-LA-ICP-MS) revealed an amphidromous life history for R. guilberti and it
suggested a progressive habitat shift from a marine habitat to a freshwater environment for P. attiti. For the first time, an
endemic species, P. attiti, showed longer and more variable PLD (55.213.5 days) than did a widespread one
(R. guilberti: ,30 days). These results need to be confirmed by analysing more samples but suggest that factors other
than the PLD control endemism and dispersal processes. In association with this first description of the biological cycle for
both species, such an approach is a prerequisite for the management and conservation of both patrimonial species.

}, keywords = {diadromy, freshwater gobies, otolith microchemistry, tropical islands.}, author = {H{\'e}l{\`e}ne Tabouret and Tomadin, Marina and Taillebois, Laura and Iida, Midori and Clara Lord and P{\'e}cheyran, C and Philippe Keith} } @article {3721, title = {Tropical and temperate freshwater amphidromy: a comparison between life history characteristics of Sicydiinae, ayu, sculpins and galaxiids.}, journal = {Rev Fish Biol Fisheries}, volume = {24}, year = {2014}, pages = {1:14}, abstract = {

Amphidromy is a distinctive form of
diadromy, but differences in the life histories of
tropical and temperate amphidromous fishes suggest
that there are two types of freshwater amphidromy.
The life histories of Sicydiinae gobies, ayu (Plecoglossus
altivelis), Japanese sculpins (Cottus) and galaxiids
(Galaxiidae), suggest that the Sicydiinae are
representatives of tropical freshwater amphidromy,
whereas ayu, sculpins and galaxiids are representatives
of temperate freshwater amphidromy. The Sicydiine
larval stage may be required to occur in the
ocean for all species, but ayu, sculpins and galaxiids
have landlocked or fluvial forms with larvae that do
not need to enter the ocean for larval feeding and
growth. This suggests that Sicydiine larvae have a high
oceanic dependency whereas ayu, sculpins and galaxiid
larvae have a low oceanic dependency. Freshwater
amphidromous fish in tropical and temperate zones
appear to have developed two different strategies in
the evolution of their life histories. It is likely that the
evolutionary direction of the larval stage of tropical
amphidromy is to remain in the sea and that of
temperate amphidromy is towards having the ability to
remain in freshwater if needed. Tropical and temperate
amphidromy appear to be biologically informative
categories and evaluations of this hypothesis will
facilitate better understanding of the various forms of
amphidromy in the future.

}, keywords = {Amphidromous species, Fluvial form, Landlocked form, Oceanic dependency, Sicydiine species}, doi = {DOI 10.1007/s11160-013-9316-8}, author = {Watanabe, S and Iida, Midori and Clara Lord and Philippe Keith and Tsukamoto, Katsumi} }