New insights from museum specimens: a case of Viviparidae (Caenogastropoda: Mollusca) in Iwakawa’s collection preserved in the National Museum of Nature and Science, Tokyo

Abstract

In this study, we clarify the classification of museum specimens of the family Viviparidae, which is composed of six species/subspecies in Japan, including three endangered species. We examined Viviparus sclateri specimens from the Tomotaro Iwakawa collection (1855-1933) in the National Museum of Nature and Science, Tokyo. The Iwakawa's collection was catalogued in 1919 and Viviparus sclateri, labelled with Naga-tanishi, the current Japanese name for H. longispira, which was, at the time, equivalent to Viviparus sclateri, was listed in this catalogue. The catalogue noted localities of Viviparus sclateri (Naga-tanishi) from outside Lake Biwa, including occurrences in Lake Kasumigaura and Lake Suwa. However, Heterogen longispira (Naga-tanishi) is currently considered to be endemic to Lake Biwa drainage. The actual status of Viviparus sclateri in Iwakawa (1919) has not been clarified until now. Our examination revealed that Viviparus sclateri from Iwakawa’s catalogue included H. japonica, H. longispira and Sinotaia quadrata histrica, based on current taxonomy. Specimens assigned to H. longispira occurred only in Lake Biwa drainage. Heterogen japonica was confirmed to be present in all lots and some H. japonica from Lake Suwa had a distinctive morphology. Sinotaia quadrata histrica was only confirmed to occur in Lake Suwa. Furthermore, some specimens from southern Lake Biwa and the Seta River had intermediate characteristics between H. japonica and H. longispira and their populations are currently almost extinct.

Quantitative analysis of the skull in the Japanese wolf (<i>Canis lupus hodophilax</i>) using CT

“…6A and C). In previous studies on the morphology of the skull in the Japanese wolf, the frontal bone did not largely protrude to the dorsal direction and the slope of the stop was gentle [17,21,37,39,44] (Fig. 6A).…”

“…yielded the same result. Regarding the morphological characteristics of the tympanic cavity in the Japanese wolf, it has been reported that it is shorter in diameter and width than that in Korean wolves [44], and Japanese wolves have ventrally flat tympanic cavities compared with other wild wolves (Fig. 8) [1,42,51].…”

“…In addition, with the development of the livestock industry in Japan, the extermination of Japanese wolves was recommended as they attacked livestock [10,15,54]. As a result, the population of the Japanese wolf decreased and a male wolf caught at Higashi Yoshino village in Nara prefecture on January 23, 1905 (38th year of Meiji) became the last Japanese wolf; therefore, this subspecies is believed to be extinct [10,15,44,54].…”

Unravelling another mystery: Parasite escape and host‐switching vary spatially in non‐indigenous populations of Japanese mystery snails

“…Globally, exotic freshwater gastropods have invaded ecosystems through multiple introduction vectors, including deliberate introductions and accidental anthropogenic transfer (Padilla & Williams, 2004). One such invader, the Japanese mystery snail ( Heterogen japonica , synonym Cipangopaludina japonica ; Saito & Kagawa, 2020), was intentionally transported from Japan to North America in c . 1911 to be cultivated for human consumption (Clench & Fuller, 1965; Prashad, 1928), but is now found in tributaries throughout North America (Jokinen, 1982; USGS, 2021).…”

“…Globally, exotic freshwater gastropods have invaded ecosystems through multiple introduction vectors, including deliberate introductions and accidental anthropogenic transfer (Padilla & Williams, 2004). One such invader, the Japanese mystery snail (Heterogen japonica, synonym Cipangopaludina japonica; Saito & Kagawa, 2020), was intentionally transported from Japan to North America in c. 1911 to be cultivated for human consumption (Clench & Fuller, 1965;Prashad, 1928), but is now found in tributaries throughout North America (Jokinen, 1982;USGS, 2021). Due to its feeding habits (i.e., filter feeder and detritivore), Heterogen japonica can improve overall water quality and productivity in invaded freshwater systems (Solomon et al, 2010;Van Bocxlaer & Strong, 2016); however, it can also negatively impact indigenous snail populations, partly due to exponential population growth in invaded systems (Johnson et al, 2009;Wolfert & Hiltunen, 1968).…”