# Identification of vitellogenic females in whitefish
(Coregonus sp) in Lake Leman (Lake Geneva)

Gérard Maisse, Bernard Breton

► To cite this version:

Gérard Maisse, Bernard Breton. Identification of vitellogenic females in whitefish (Coregonus sp) in Lake Leman (Lake Geneva). Symposium on coregonid fishes, Oct 1984, Thonon Les Bains, France. 386 p. hal-01600791

HAL Id: hal-01600791

https://hal.science/hal-01600791

Submitted on 4 Jun 2020

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution - ShareAlike 4.0 International License
<table><tr><td>Arch. Hydrobiol. Beih.<br>Ergebn. Limnol.</td><td>22</td><td>299-301</td><td>Stuttgart, Juni 1986</td></tr></table>

# Identification of vitellogenic females in whitefish (*Coregonus* sp.) in Lake Léman (Lake Geneva)

By G. MAISSE and B. BRETON, Rennes

With 2 tables in the text

## Abstract

Vitellogenin from whitefish of Lake Léman shows immunological similarities to that of rainbow trout using immunodiffusion studies; this fact allows the detection of vitellogenin in the blood of mature females. The serodiagnosis is proposed for the identification of vitellogenic whitefish females.

## 1. Introduction

Good management of fisheries first depends upon a good knowledge of the dynamics of the exploited populations. The first point to study is the stock-recruitment relationships (Pitcher & Hart, 1982), for which the number of vitellogenic females must be well known as soon as possible before the spawning period.

In salmonids several methods of sex determination using sexual dimorphism or blood parameters (such as vitellogenin, steroid levels...) have been used (Le Bail, 1981; Le Bail & Fostier, 1984) depending upon the age of the animals, and the technical possibilities offered by the experimental conditions in the field or in the laboratory (Maisse, 1982). In whitefish (*Coregonus* sp.) breeding tubercles appear during the spawning season (Koelz, 1929 in Norden, 1961; Wiley & Colette, 1970). In Lake Léman species these tubercles are more pronounced in males than in females (Champigneulle, pers. comm.). Out with the spawning season, it is not possible to distinguish between the two sexes.

In this work we have tested the possibility offered by the immunoagglutination technique developed in salmonids (Le Bail & Breton, 1981), using an antibody developed against the vitellogenin of rainbow trout (*Salmo gairdneri*) to sex the whitefish.

## 2. Material and methods

The whitefish were caught during the special fisheries of spawners organized in Lake Léman in December 1984. The general characteristics of these animals have already been described by Champigneulle et al. (1983). In 1982 the spawners were mostly 1⁺ year of age, but in 1984, year of the study, they were mostly 2⁺ and 3⁺ with a total length comprised between 40 and 50 cm.

Blood samples were taken by caudal puncture using a heparanized seringe (100 UI/ml) either from live or recently dead animals. The sex was determined after stripping eggs or milt or after autopsy.
The purification of the vitellogenin from rainbow trout sera, the antibody preparation and the immunodiffusion and immunoagglutination techniques have already been described (Le Bail & Breton, 1981) and extended to the determination of the vitellogenin in the whole blood (Le Bail et al., 1981).

### 3. Results

Using the immunodiffusion only sera from the females give a precipitation line with the antibody directed against the rainbow trout vitellogenin: there is an intersection between this line and the one obtained with a serum of rainbow trout. The precipitation line is obtained at all dilutions less than 1/8 of the whitefish serum (Table 1).

In 2 µl of diluted blood treated with 20 µl of vitellogenin sensibilized latex particles in immunoagglutination, the presence of vitellogenin is revealed at dilutions 1 and 1/2 (Table 1). Following from these results, the dilution 1 (2 µl of neat blood) has been chosen as the working dilution.

The immunoagglutination allowed the correct sexage of the totality of an experimental group of 57 fishes (25 males and 32 females) (Table 2).

<table><caption>Table 1. Presence of vitellogenin detected with the immunoagglutination and immunodiffusion tests in, respectively, diluted blood and sera of females whitefish in December 1984.</caption><thead><tr><th rowspan="2">Test</th><th colspan="6">Blood or sera dilution</th></tr><tr><th>1</th><th>1/2</th><th>1/4</th><th>1/8</th><th>1/16</th><th>1/32</th></tr></thead><tbody><tr><td>Immunoagglutination</td><td>*</td><td>*</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Immunodiffusion</td><td>+</td><td>+</td><td>+</td><td>+</td><td>-</td><td>-</td></tr></tbody></table>

<table><caption>Table 2. Results of sexage with immunoagglutination test (2 µl of neat blood + 20 µl of vitellogenin sensibilized latex particles) in an experimental group of whitefish.</caption><thead><tr><th>Sex</th><th>Total number</th><th>No. of samples with vitellogenin</th><th>No. of correct sexages</th></tr></thead><tbody><tr><td>Male</td><td>25</td><td>0</td><td>25</td></tr><tr><td>Female</td><td>32</td><td>32</td><td>32</td></tr></tbody></table>

### 4. Discussion and conclusion

As shown by the immunodiffusion, the whitefish vitellogenin is not identical to the rainbow trout vitellogenin, but possesses enough immunological similarities to cross react with an antibody directed against this protein using immunodiffusion and immunoagglutination, thus allowing the use of these two techniques for the sexage of whitefish. The immunological identity of the rainbow trout vitellogenin

<footnote>* High level of vitellogenin causing saturation of the antibody.</footnote>
with those of *Salmo trutta*, *Salmo salar*, *Oncorhynchus kisutch* and *Salvelinus alpinus* has been shown by Le Bail (1981). Our results extend the use of serodiagnosis of vitellogenic females to the coregonids.

The fact that a cross-reaction can be obtained using more diluted blood or sera indicates that the tests might be used earlier in the reproductive cycle. It would be necessary to precise the periods at which the vitellogenin could be revealed either by immunoagglutination or immunodiffusion which ever seems the more sensitive technique and to compare these periods with those at which sexual dimorphism is not visible. If, as can be supposed, the agglutination test was usable earlier than the apparition of breeding tubercles on the animal's flanks, studies on the reproductive potential of whitefish could be envisaged a long time before spawning as is commonly done now in salmonids such as the brown trout (*Salmo trutta*) (Bagliniere et al., 1981) and the Atlantic salmon (*Salmo salar*) (Prouzet et al., 1984).

## Acknowledgements

The authors would like to thank A. Champigneulle and C. Gillet who participated in the collection of samples. Financial support was provided by ATP I. N. R. A. 4355 "connaissance et gestion des écosystèmes lacustres subalpins".

## References

* Bagliniere, J. L., Le Bail, P. Y. & Maisse, G. (1981): Détection des femelles de Salmonidés en vitellogenèse: 2) un exemple d'application: recensement dans la population de Truite commune (*Salmo trutta*) d'une rivière de Bretagne Sud (le Scorff). - Bull. Fr. Pisc., **283**: 89-95.

* Le Bail, P. Y. (1981): Identification du sexe en fonction de l'état de maturité chez les poissons. - Thèse de Docteur-Ingénieur, Univ. de Rennes, 71 pp.

* Le Bail, P. Y. & Breton, B. (1981): Rapid determination of the sex of puberal salmonid fish by a technique of immunoagglutination. - Aquaculture, **22**: 367-375.

* Le Bail, P. Y. & Fostier, A. (1984): Techniques d'identification du sexe et d'estimation de la maturité sexuelle chez les poissons vivants. - In: G. Barnabe & R. Billard, eds., L'Aquaculture du Bar et des Sparidés. I. N. R. A. Publ. Paris, 1984: 45-52.

* Le Bail, P. Y., Maisse, G. & Breton, B. (1981): Détection des femelles de Salmonidés en vitellogenèse: 1) description de la méthode et mise en oeuvre pratique. - Bull. Fr. Pisc., **293**: 79-88.

* Maisse, G. (1982): Methods of identification of sex according to the stage of maturity in salmonids that have been kept alive: application to the study of the dynamics of wild populations. - Abstract, Fourth Congress of Europ. Ichthyologists 1982.

* Norden, C. R., (1961): Comparative osteology of representative salmonid fishes with particular reference to the Grayling (*Thymallus articus*) and its phylogeny. - J. Fish. Res. Bd. Can., **18** (5): 679-791.

* Pitcher, T. J. & Hart, P. J. B. (1982): Fisheries ecology. - Croom Helm, London/Canberra, 414 pp.

* Prouzet, P., Le Bail, P. Y. & Heydorff, M. (1984): Sex ratio and potential fecundity of Atlantic salmon (*Salmo salar*) caught by anglers on the Elorn river (Northern Brittany, France) during 1979 and 1980. - Fish. Mgmt. **15** (3): 123-130.

* Wiley, M. L. & Colette, B. B. (1970): Breeding tubercles and contact organs in fishes: their occurrence, structure and significance. - Bull. Amer. Mus. Nat. Hist., **143**: 143-216.

Authors' address:

I. N. R. A., Laboratoire de Physiologie des Poissons, 35042 Rennes Cedex, France