Morphology-based taxonomic re-assessment of the Arctic lamprey, Lethenteron camtschaticum (Tilesius, 1811) and taxonomic position of other members of the genus

The lamprey genus Lethenteron Creaser & Hubbs, 1922 is widespread across Eurasia and North America, but the number and distribution of its constituent species is not firmly established. After a morphological examination of extant type material of the currently recognized species and their synonyms, Lethenteron mitsukurii (Hatta, 1901) is resurrected with Le. matsubarai Vladykov & Kott, 1978 as its junior synonym. Amongst nonparasitic species Le. reissneri (Dybowski, 1869) and Le. mitsukurii are confirmed as present in Japan and the former is also present on Sakhalin. An in-depth study of large samples of nonparasitic lamprey adults from Japan and Sakhalin Island is needed to determine whether the lower trunk myomere (< 66) individuals from these areas represent one or more undescribed species, or Le. mitsukurii, or Le. reissneri, or a mixture of these three alternatives. The material from the Anadyr Estuary identified by Berg (1931, 1948) as Lampetra japonica kessleri has been re-identified as Le. camtschaticum and there is no evidence that Le. kessleri occurs there. Lethenteron reissneri is reported from the Angara River system, Yenisei River drainage, Russia. Lethenteron alaskense Vladykov & Kott, 1978 is provisionally considered to be a junior synonym of Le. kessleri (Anikin, 1905). Petromyzon ernstii Dybowski, 1872, Ammocoetes aureus Bean, 1881, Petromyzon dentex Anikin, 1905, Lampetra mitsukurii major Hatta, 1911, and Lampetra japonica septentrionalis Berg, 1931 are junior synonyms of Petromyzon marinus camtschaticus Tilesius, 1811. A key is provided to adults of the six species recognized as belonging in the genus Lethenteron.

Aннотированный список рыбообразных и рыб водоемов и водотоков бассейна верхнего Иртыша Восточного Казахстана с комментариями по их таксономии и зоогеографии

Приводится список рыбообразных и рыб, обитающих в водоемах и водотоках бассейна Верхнего Иртыша. Список содержит 43 вида, относящихся к 7 отрядам, 10 семействам и 30 родам. Включены все зарегистрированные на настоящий момент виды, валидность которых была пересмотрена в соответствующих систематических ревизиях. Три вида таймень Hucho taimen Pallas, 1773, нельма Stenodus leucichtys nelma Pallas, 1773, сибирский осетр Acipenser baerii Brandt, 1869 внесены в Красную Книгу Республики Казахстан. В бассейне Верхнего Иртыша к редким ценным видам, нуждающимся в сохранении генофонда из-за возможности его утраты, кроме уже внесенных в Красную Книгу Республики Казахстан можно отнести еще ряд видов: минога тихоокеанская Lethenteron camtschaticum Tilesius, 1811, стерлядь Acipenser ruthenus Linnaeus, 1758 маркакольский ленок Brachymystax savinovi Mitrofanov 1959.

Utilizing DNA metabarcoding to characterize the diet of marine-phase Arctic lamprey (Lethenteron camtschaticum) in the eastern Bering Sea

To understand the marine feeding ecology of Arctic lamprey (Lethenteron camtschaticum) in the eastern Bering Sea, visual observations and DNA metabarcoding of gut contents (N = 250) were used to characterize Arctic lamprey diet composition in 2014 and 2015. Differences among individual diets were evaluated by collection year, capture site, and fish size. Hard structures and tissues were observed during visual examinations of gut contents, and 10 ray-finned fish taxa were identified by DNA metabarcoding. The most frequently observed taxa included capelin (Mallotus villosus), Pacific herring (Clupea pallasii), Pacific sand lance (Ammodytes hexapterus), and gadids. Six taxa were reported for the first time as prey for Arctic lamprey. Individual diets differed between collection years, among capture sites, and among size classes; however, both collection year and size class explained only a small portion of diet variability (R2 = 0.01 and 0.04, respectively) relative to capture site (R2 = 0.49). These study results indicate that Arctic lamprey is a flesh-feeding species and highlight the value of DNA metabarcoding to characterize the diet of a poorly understood lamprey species.