Predicting distributions of seven bitterling fishes in northern Kyushu, Japan

Abstract

The distributions of seven bitterling species and subspecies-Tanakia lanceolata, T. limbata, Acheilognathus tabira nakamurae, A. rhombeus, Rhodeus ocellatus kurumeus, R. ocellatus ocellatus, and R. atremius atremius-in northern Kyushu were predicted using generalized linear models (GLMs) in order to provide information helpful for conserving native bitterlings and preventing the expansion of alien bitterling species. Predictions were made according to the following procedure: (1) a set of GLMs for each species was formulated using environmental data from 710 sites that were derived using digital maps and GIS software, from which the best fit model for each species was selected using the Akaike information criterion for predicting the fish occurrence, (2) model performance was evaluated based on the receiver-operating characteristics (ROC) analysis using occurrence and environmental data from 362 sites, and (3) potential distributions of the bitterling were analyzed using the best fit models and environmental data for 1,272 sites, of which 200 data points without occurrence data were prepared.The best fit models revealed that 4-6 environmental factors were important in predicting seven bitterling distributions, which was supported by the area under the ROC curve (AUC) values of these fishes ranging from 0.753 to 0.927.The AUC values in model evaluation were significantly greater than 0.5 for six fishes, suggesting the moderate accuracies of these best fit models for predicting the fish distributions. These predictive models can be used for evaluating potential native bitterling richness and the potential distribution expansion of an alien subspecies.

Should species distribution models use only native or exotic records of existence or both?

“…Thuiller (2003) also noted that even with the use of three datasets at various locations, scales and resolutions, there was no evidence that one particular technique was consistently more accurate than others. Readers interested in other model comparisons or comparison of different range of data may refer to Brotons et al (2004), Vayssières et al (2000), Fukuda et al (2013) and Onikura et al (2012).…”

Molecular Phylogeny and Conservation Priorities of the Subfamily Acheilognathinae (Teleostei: Cyprinidae)

“…Onikura et al (2012) remarked that "Sixteen species or subspecies of bitterling are present in Japan. Because most of these fishes are endemic, Japan is regarded as a hotspot of bitterling diversity.…”

“…Rhodeus smithii and Acheilognathus elongatus are listed as Critically Endangered, four species, Tanakia tanago, R. laoensis, R. atremius, and A. longipinnis, are listed as Vulnerable, and ~25% of other species are categorized as Data Deficient by the IUCN (International Union for Conservation of Nature) (http://www.iucnredlist.org/). Wild populations of most species in Acheilognathinae are considered to be in decline, and some species are predicted to become extinct in the future (Onikura et al, 2012). The extinction crisis of Acheilognathinae has been attributed to habitat loss and fragmentation, climate change, invasive species, and interactions among multiple threats (Katano and Mori, 2005;Chang et al, 2009;Kubota et al, 2010).…”

“…Particularly, acheilognathines may suffer more extinction pressure than other cyprinids due to their unusual spawning relationship with freshwater mussels, as they only use the interlamellar spaces of paired inner and outer gills of living unionid freshwater mussels as a spawning substrate (Okazaki et al, 2001;Katano and Mori, 2005). To avert or mitigate the extinction risk, a set of conservation priorities for Acheilognathinae are urgently needed (Katano and Mori, 2005;Onikura et al, 2012).…”

Potential distribution of Tridentiger barbatus (Günther 1861) and Tridentiger nudicervicus (Tomiyama 1934) in the Seto Inland Sea, western Japan

“…These models have been applied to terrestrial conservation and restoration programs, providing an effective first step toward establishing land management priorities (Scott et al 2002). In recent years, studies of freshwater fishes using SDMs based on GIS have been increasing in Japan (Kano et al 2010;Sato et al 2010;Onikura et al 2012). However, previous research focusing on shallow water fishes had been limited to species considered as important fishery resources such as red sea bream and flounder (Hori 2012).…”