Recenti ricerche sulle forme « appaiate » di Lamprede dell'Italia e del Danubio

Zanandrea, I. S. Giuseppe

doi:10.1080/11250005909439307

Cited by 14 publications

(7 citation statements)

References 7 publications

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“…For this reason, the mature adult rareIy exceeds 18 cm, the maximum size reached by the ammocoete. The River and Brook lampreys constitute a "paired species" (Zanandrea, 1959~) consisting of both a proposed ancestral and a derivative species, of which there are apparently many examples in the extant lamprey fauna (Hardisty & Potter, 19716;Hubbs & Potter, 1971).…”

Section: Introductionmentioning

confidence: 99%

The systematics of British larval lampreys

Potter

Osborne

1975

Journal of Zoology

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Several taxonomic characters, including the number of trunk myomeres, proportional body measurements and patterns of external and internal pigmentation, have been investigated in populations of ammocoetes belonging to the three species of lampreys found in British rivers. Petromyzon marinus can be readily distinguished by the pigmentary pattern in the tail and on the oral hood, and by the much higher number of trunk myomeres. Although no character can be used to separate with certainty the larvae of Lampetra fluviatilis and Lampetra planeri, significant differences were found between the mean number of trunk myomeres in the two species. Moreover, the values for ammocoetes were virtually identical to those of the respective post‐larval stages, at which phase in the life cycle the two Lampetra species are clearly distinguishable. The incidence of pigmentation on the tongue precursor was much higher in larval populations of L. fluviatilis than in those of L. planeri and there was also a difference in the rate of change in the relative length of the trunk and tail. Where comparisons can be made, the results in this paper are in agreement with those of most other European and North American workers. The data differ markedly, however, from that contained in the only other previous detailed systematic study on British larval lampreys, which was subsequently used as the basis for taxonomic keys.

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Section: Introductionmentioning

confidence: 99%

The systematics of British larval lampreys

Potter

Osborne

1975

Journal of Zoology

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“…Lampetra richardsoni is a close relative of the anadromous parasitic Lampetra ayresi, and they are considered to be a species pair (Zanandrea 1959;Vladykov and Kott 1979;Potter 1980). The evolutionary relationship between members of a species pair remains uncertain, although there is a widely accepted view that the non-parasitic form evolved from.…”

Section: Special Significancementioning

confidence: 99%

“…It should be noted that the variety has not been given *Reviewed and approved by COSEWIC April 1999, status assigned -Threatened official taxonomic status, despite its distinctive life history and morphology relative to Lampetra richardsoni. The variety is parasitic in the laboratory and the taxonomy of lampreys uses adult life history type as a species specific character (Zanandrea 1959;Vladykov and Kott 1979;Potter 1980). Therefore, in a sense, this population produces two species according to conventional lamprey taxonomy.…”

mentioning

confidence: 99%

Status of the Morrison Creek Western Brook Lamprey, Lampetra richardsoni, in Canada

Beamish,

Youson,

Chapman

2001

The Canadian Field-Naturalist

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The Morrison Creek Western Brook Lamprey, is a distinct and rare population of the widely distributed Western Brook Lamprey, Lampetra richardsoni, and it is endemic to a small creek on Vancouver Island, Canada. This special population produces both non-parasitic and potentially parasitic adult life history types, representing a unique type of polymorphism in jampreys. The Morrison Creek population demonstrates that a linkage between parasitic and non-parasitic lampreys exists and provides an opportunity to study lamprey speciation and evolution. However, this rare population is at risk because its habitat is currently facing substantial development pressures. The Morrison Creek Lampetra richardsoni population should be protected because of its important implications for our understanding of lamprey taxonomy and evolution, and because the potentially parasitic variety needs further study as it represents a life history that is difficult to classify with our existing knowledge.La lamproie du ruisseau Morrison, Lampetra richardsoni, est endémique dans un petit cours d'eau de l'ile de Vancouver, Canada; elle représente une forme distincte et rare de la lamproic de l'ouest, Lampetra richardsoni, qui, elle, jouit d'une grande distribution. Le ruisseau abrite les deux formes de L. richardsoni et celles-ci forment une population unique de lamproies qui produit des types biologiques adultes a la fois parasitiques et non parasitiques. Cette population polymorphe est un phénoméne unique en son genre chez la lamproie dont l'ascendance remonte a au moms 350 millions d'années. Ce qui se passe dans le ruisseau Morrison revét donc une grande pertinence pour ce qui est de la compréhension de |' évolution des premiers vertébrés. Toutefois, cette population rarissime est en danger car son habitat subit actuellement d' importantes pressions d'aménagement. I] est impératif que nous préservions le complexe des deux formes de la lamproie du ruisseau Morrison puisqu'il présente des implications importantes pour la compréhension de la taxonomie et de |'évolution de la lamproie et que la variété est un cas qu'il est difficile de classer dans |' état actuel des connaissances.

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“…Before the construction of the Volga Hydroelectric Station (1958), the Volga river system was almost entirely populated by the Caspian lamprey Caspiomyzon wagneri, an anadromous species, which does not form freshwater populations or satellite (paired) freshwater species [7,9]. These lampreys used to go up the Volga as far as the city of Kalinin (now Tver) and the mouth of the Tvertsa River [10].…”

Section: Introductionmentioning

confidence: 99%

European River Lamprey Lampetra Fluviatilis in the Upper Volga: Distribution and Biology

Zvezdin

Kucheryavyy

Kolotei

et al. 2021

Preprint

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After the construction of the Volga Hydroelectric Station and other dams, migration routes of the Caspian lamprey were obstructed. The ecological niches vacated by this species attracted another lamprey of the genus Lampetra to the Upper Volga, which probably came from the Baltic Sea via the system of shipways developed in the 18 th and 19 th centuries. Based on collected samples and observations from sites in the Upper Volga basin, we provide diagnostic characters of adults, and information on spawning behavior. Silver coloration of Lampetra fluviatilis was noted for the first time and a new size-related subsample of “large” specimens was delimited, in addition to the previously described “dwarf”, “small” and “common” adult resident sizes categories. The three water systems: the Vyshnii Volochek, the Tikhvin and the Mariinskaya, are possible invasion pathways, based on the migration capabilities of the lampreys. Dispersal and colonization of the Caspian basin was likely a combination of upstream and downstreams migrations. First, the lampreys migrated upstream along the rivers of the Baltic basin until they reached the water-parting line, followed by mostly downstream dispersal into rivers of the Caspian basin. Dispersal in the Volga River was similar, in accordance with the migration cycle of this opportunistic lamprey species.

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Recenti ricerche sulle forme « appaiate » di Lamprede dell'Italia e del Danubio

Cited by 14 publications

References 7 publications

The systematics of British larval lampreys

The systematics of British larval lampreys

Status of the Morrison Creek Western Brook Lamprey, Lampetra richardsoni, in Canada

European River Lamprey Lampetra Fluviatilis in the Upper Volga: Distribution and Biology

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