Flexible seaward migration of Dolly Varden Salvelinus malma in the Shiretoko Peninsula, Hokkaido, Japan

Umatani, Yoshiyuki; Arai, Takaomi; Maekawa, Koji

doi:10.1007/s10228-017-0606-3

Cited by 5 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the latter regions, southern Asian Dolly Varden are land-locked in the upper reaches of the rivers (Fausch et al 1994;Takami et al 1995). However, in the rivers of eastern Hokkaido Island, some individuals of the fish exhibit anadromy (Hikita 1962;Ishigaki 1967;Maekawa 1973;Komi-yama et al 1982;Morita et al 2005;Kasugai et al 2016;Umatani et al 2018), and there are records of S. edwardsii from the same fish species caught in the coastal sea (Olya Inlet and Kuibyshev Bay) of Iturup Island (localities 1 and 2 in Fig. 3) (Shedko and Shedko 2002).…”

Section: Discussionmentioning

confidence: 99%

Salmincola edwardsii (Copepoda: Lernaeopodidae) Parasitic on Southern Asian Dolly Varden, Salvelinus malma krascheninnikova, from Hokkaido Island, Japan, with the Southernmost Distribution Record of the Copepod in Asia

Nagasawa

2020

Spec.Div.

View full text Add to dashboard Cite

Females of the lernaeopodid copepod Salmincola edwardsii (Olsson, 1869) were found parasitizing the gill area of southern Asian Dolly Varden, Salvelinus malma krascheninnikova Taranetz, 1933, from four rivers (Rusha River, Rausu River, Shari River, Shibetsu River) in and near the Shiretoko Peninsula, eastern Hokkaido Island, Japan. The females are briefly described as the first record of S. edwardsii from Hokkaido Island and the southernmost distribution record for the species in Asia. The branchial chamber was the most frequently used site for attachment by the females, followed by the gill filaments and the inner surface of the operculum. The overall prevalence of infection was 42.1%, and intensity ranged from 1 to 6 (mostly 1 or 2). The species was not collected from the central and western regions of Hokkaido Island, and the restriction of its distribution to eastern Hokkaido Island is discussed in terms of anadromy of the host species. The impact of global climatic warming on the Hokkaido populations of S. edwardsii is also discussed.

show abstract

Section: Discussionmentioning

confidence: 99%

Salmincola edwardsii (Copepoda: Lernaeopodidae) Parasitic on Southern Asian Dolly Varden, Salvelinus malma krascheninnikova, from Hokkaido Island, Japan, with the Southernmost Distribution Record of the Copepod in Asia

Nagasawa

2020

Spec.Div.

View full text Add to dashboard Cite

show abstract

“…One possible explanation for the variation in the occurrence of early descending may be the degree of the river gradient. Several previous otolith microchemistry studies on sympatric salmonid species have also identified pre-smolt migrants from steep-gradient rivers (e.g., masu salmon Oncorhynchus masou, Kuroki et al 2020; southern Asian Dolly Varden Salvelinus curilus, Umatani et al 2018; Table 3). Due to their limited swimming capability, juvenile fish are likely to be displaced downstream (Lechner et al 2016).…”

Section: Resultsmentioning

confidence: 96%

Diverse migration patterns of anadromous white-spotted charr Salvelinus leucomaenis revealed from otolith microchemistry

Goto,

Kuroki,

Shirai

et al. 2024

Ichthyol Res

View full text Add to dashboard Cite

Anadromous migration of salmonid fish has been extensively studied, primarily focusing on the dichotomous framework of anadromy and residency. However, there remains a limited understanding of intermediate migratory behaviors within the anadromous framework. Our study aimed to classify the lifetime migration patterns of the anadromous white-spotted charr Salvelinus leucomaenis within and among populations using otolith annuli and Sr:Ca ratios. Initially, the migratory histories of anadromous charr were divided into two stages: “virgin sea-run stage” and “veteran sea-run stage”. The former was further categorized into three types: ocean entry at age ≥1+ years old, early descending, and brackish use. The latter was grouped into four types: annual migrants, frequent migrants, retired migrants, and ocean residents. We found that the proportion of migration patterns varied among rivers, with multiple patterns coexisting within the same river. Migration patterns typically involving 1–5 years spent in freshwater rivers followed by annual oceanic migrations were the most abundant, although diverse patterns were also observed. In the virgin sea-run stage, some individuals experienced the ocean at age 0+ years or brackish environments before their first sea entry. In the veteran sea-run stage, we found individuals who had resided in either the ocean or rivers for over a year. Retired migrants, characterized by stopping oceanic migration at a certain age and subsequently spending time in rivers, were exclusive to southern rivers. Conversely, ocean residents who spend one or more years in the ocean were more frequent in northern regions. Consequently, the lifetime migration patterns of anadromous white-spotted charr may exhibit stronger ocean dependency at higher latitudes. The implications of this study highlight the complexity and flexibility of migratory behaviors within and among white-spotted charr populations.

show abstract

“…In 2004, 84 native Dolly Varden charr were caught in the nearby Pon‐horomoi River and transplanted to the Orumappu River, because anadromous Dolly Varden charr are rare in this region (Morita et al, 2005; Umatani et al, 2018) and natural immigrations from neighboring rivers were considered unlikely. Age‐0 fry, the offspring of reintroduced individuals, have been caught each year since, indicating continued, successful reproduction of native Dolly Varden charr in this river (Figure A1).…”

Section: Non‐native Species Decline and Native Species Recoverymentioning

confidence: 99%

Ups and downs of non‐native and native stream‐dwelling salmonids: Lessons from two contrasting rivers

Morita

2022

Ecological Research

View full text Add to dashboard Cite

Freshwater rivers and lakes are particularly vulnerable to anthropogenic disturbance because of their proximity to human occupation. Anthropogenic impacts in fresh water include those caused by dams, water pollution, channelization, and invasive species. One common action to conserve freshwater biodiversity involves supplementing or reintroducing extirpated species, though the benefits of these efforts are controversial. Installation of fishways to dams and removal of invasive alien species has also resulted in recovery of native species. Herein results of long‐term monitoring of salmonids in two rivers in Japan are presented. The first case involves a river above a dam where native white‐spotted charr Salvelinus leucomaenis and masu salmon Oncorhynchus masou declined rapidly in number following dam construction, where non‐native rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta increased in number, and where stocking of native masu salmon was unsuccessful. The second case involves a river formerly dominated by non‐native rainbow trout, in which native Dolly Varden charr Salvelinus curilus and masu salmon increased in numbers following removal of non‐native species and fishway installation. Results reveal natural recovery of masu salmon in a river within which they were once completely extirpated, without stocking. Because salmonids are migratory fish and return to natal rivers, when locally extinct, human intervention to stock or reintroduce them has often been deemed necessary. However, restoration of wildlife would not require stocking or reintroduction if factors that impede the self‐recovery capability of species are removed.

show abstract

Flexible seaward migration of Dolly Varden Salvelinus malma in the Shiretoko Peninsula, Hokkaido, Japan

Cited by 5 publications

References 18 publications

<i>Salmincola edwardsii</i> (Copepoda: Lernaeopodidae) Parasitic on Southern Asian Dolly Varden, <i>Salvelinus malma</i> <i>krascheninnikova</i>, from Hokkaido Island, Japan, with the Southernmost Distribution Record of the Copepod in Asia

<i>Salmincola edwardsii</i> (Copepoda: Lernaeopodidae) Parasitic on Southern Asian Dolly Varden, <i>Salvelinus malma</i> <i>krascheninnikova</i>, from Hokkaido Island, Japan, with the Southernmost Distribution Record of the Copepod in Asia

Diverse migration patterns of anadromous white-spotted charr Salvelinus leucomaenis revealed from otolith microchemistry

Ups and downs of non‐native and native stream‐dwelling salmonids: Lessons from two contrasting rivers

Contact Info

Product

Resources

About