Observations on movements of yellow eels, Anguilla anguilla L., after displacement from coastal waters to sea

The retinae of all the species of deep-sea fish which have been studied have been shown to contain golden coloured pigments, chrysopsins, which are especially suited to the light found in their natural environment (Denton & Warren, 1957; Munz, 1958). Amongst fish caught in shallow coastal waters this characteristic colour of retinal pigment is found only in the conger eel Conger conger (by Denton & Walker, 1958), and amongst freshwater fish only in the silver eel Anguilla anguilla (by Carlisle & Denton, 1957, referred to by Denton & Warren, 1957). Both these fish are species of Apodes, a group of which the vast majority of species are deep-water forms. Both species, more- over, begin their life in the deep sea and return to it again when mature to spawn and may therefore, in one sense, be regarded as deep-sea fish. Since immature conger eels in shallow coastal waters already have a retinal pigment characteristic of a deep-sea fish, it seems very unlikely that on returning to deep water they would change away from the deep-sea form which they already possess. It is probable therefore that the conger retains a deep-sea form of retinal pigment throughout the whole of its life.

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Early back-calculated size-at-age of Atlantic yellow eels sampled along ecological gradients in the Gironde and St. Lawrence hydrographical systems

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2017-0025 ◽

2018 ◽

Vol 75 (8) ◽

pp. 1270-1279 ◽

Cited By ~ 1

Author(s):

Géraldine Patey ◽

Catherine M. Couillard ◽

Hilaire Drouineau ◽

Guy Verreault ◽

Fabien Pierron ◽

...

Keyword(s):

Genetic Selection ◽

Anguilla Anguilla ◽

Habitat Choice ◽

Early Growth ◽

First Year ◽

Sampling Program ◽

Size At Age ◽

American Eels ◽

Current Paradigm ◽

Yellow Eels

An international sampling program investigating the causes of the decline of American eels (Anguilla rostrata) and European eels (Anguilla anguilla) in the St. Lawrence (Canada) and Gironde (France) rivers systems provided the opportunity to compare early growth of eels of each species among habitats using back-calculated size-at-age from 1 to 5 years old. Our study supports previous studies showing that the early back-calculated lengths of A. anguilla were higher in downstream and more saline Gironde system habitats than in the upstream fluvial section and provides a new indication that length at 1 year old is twice higher than that reported 10 years earlier. However, our data contradict the current paradigm for A. rostrata by providing evidence that early size-at-age of eels from the upstream St. Lawrence system, most distant from the spawning area, exceeds those of eels sampled downstream, at less distant sites in the estuarine section. Overall, these observations are consistent with the hypothesis that the observed spatial variations in early growth rate of yellow eels sampled in the St. Lawrence and Gironde systems are the consequence of processes occurring in the first year of age, such as genetic selection and (or) genetically dependent habitat choice.

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Age determination and growth of yellow eels, Anguilla anguilla (L.), from a brackish water, Norway

Journal of Fish Biology ◽

10.1111/j.1095-8649.1985.tb04292.x ◽

1985 ◽

Vol 26 (5) ◽

pp. 521-525 ◽

Cited By ~ 25

Author(s):

L. A. Vollestad

Keyword(s):

Brackish Water ◽

Age Determination ◽

Anguilla Anguilla ◽

Yellow Eels

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