Comparative larval development of three amphidromous Rhinogobius species, making reference to their habitat preferences and migration biology

Abstract

Abstract. Eggs and larvae of three amphidromous species of Rhinogobius goby (Rhinogobius brunneus, Rhinogobius sp. MO and Rhinogobius sp. CB) from Okinawa Island, Japan, were reared under uniform conditions to describe and compare their larval development. Although the larval morphologies of the three species were very similar, some differences were observed in the timing of ontogenetic events among them. R. brunneus had the largest yolk and saved it for a longer period of time, whereas Rhinogobius sp. MO had the smallest yolk, which was exhausted earlier. The period until yolk exhaustion is thought to restrict the distance that migrating larvae can drift, which determines the specific adult distribution. Each of these two amphidromous species are close relatives of different fluvial resident species. Evolution of the fluvial residents could be explained by different scenarios based on the larval traits of R. brunneus and Rhinogobius sp. MO. Rhinogobius sp. CB hatched at a smaller size and grew slower than the other two species. No fluvial species have derived from Rhinogobius sp. CB. One possible explanation is that the smaller and slower-growing larvae of Rhinogobius sp. CB find it more difficult to remain within streams.

Life histories of closely related amphidromous and non‐migratory fish species: a trade‐off between egg size and fecundity

“…Our meta-analysis results are consistent with previous observations that non-migratory species generally have larger eggs than closely related amphidromous species (McDowall, 1970(McDowall, , 2009Goto, 1990;Katoh & Nishida, 1994;Goto et al, 2002;Goto & Arai, 2003;Maruyama et al, 2003;Yokoyama & Goto, 2005;Kondo et al, 2013). This paper represents the first comprehensive crosstaxon review of this phenomenon and confirms that it is a generalised trait.…”

“…Given that amphidromous species produce small pelagic larvae and that there is unlikely to be any significant advantage of increasing larval size at the expense of fecundity, we hypothesised that egg size will be relatively small and constant irrespective of adult size, resulting in a strong positive relationship between adult size and fecundity. In contrast, for non-migratory galaxiids (and particularly fluvial species), increased egg and larval size have the potential to improve larval survival substantially, partic-ularly in less productive freshwater environments (Tamada, 2005(Tamada, , 2009Tamada & Iwata, 2005;Kondo et al, 2013). Hence, we hypothesised that in these species increased adult size will tend to be more strongly associated with increased egg size rather than higher fecundity.…”

“…In contrast, for non-migratory galaxiids (and particularly fluvial species), increased egg and larval size have the potential to improve larval survival substantially, partic-ularly in less productive freshwater environments (Tamada, 2005(Tamada, , 2009Tamada & Iwata, 2005;Kondo et al, 2013). First we examine the variation in egg size (as a proxy for larval size) amongst amphidromous and non-migratory species of fish in the families Galaxiidae, Cottidae, Eleotridae and Gobiidae.…”

Complete mitochondrial genome and phylogenic analysis of Rhinogobius cliffordpopei (Perciformes, Gobiidae)

“…It is time for people to take measures to control the fish's reproduction. However, only a few kinds of research have studied on it (Wu and Zhong 2008;Kondo et al 2013). So, we determined the mtDNA of R. cliffordpopei for the first time and compared with the mtDNA (GenBank: KP 892753) of Rhinogobius giurinus, which has highly similar phenotypes with the former.…”

Ecosystem size predicts the probability of speciation in migratory freshwater fish

“…Divergent selection between flowing and staying larvae would become stronger in longer rivers (i.e., larger ecosystems), as the spawning sites of AF are restricted within a certain distance from the sea owing to the mortality of drifting larvae (see above; Moriyama et al, 1998; Omori et al, 2012). Furthermore, divergent selection might have been stronger during glacial periods, when sea level was lower, and hence rivers became longer (Kondo et al, 2013). Therefore, the landscape in the period of low sea level might have affected patterns of speciation.…”