Sexually mature European eels (Anguilla anguilla L.) stimulate gonadal development of neighbouring males: possible involvement of chemical communication. | - CCMAR -

Journal Article

TítuloSexually mature European eels (Anguilla anguilla L.) stimulate gonadal development of neighbouring males: possible involvement of chemical communication.
Publication TypeJournal Article
AuthorsHuertas, M, Scott, AP, Hubbard, PC, Canario, AVM, Cerdà, J
Year of Publication2006
JournalGen Comp Endocrinol
Volume147
Questão3
Date Published2006 Jul
Pagination304-13
ISSN0016-6480
Palavras-chaveAnguilla, Animal Communication, Animals, Female, Gonadal Steroid Hormones, Gonads, Male, Olfactory Mucosa, Sex Attractants, Sexual Maturation, Spermatogenesis, Water
Abstract

This study was aimed to investigate whether sexual maturation of immature male eels could be stimulated indirectly by placing them in contact with either male (Minj) or female (Finj) eels in which sexual maturation had been stimulated directly by weekly injections of human chorionic gonadotropin (hCG) or salmon pituitary extract (SPE), respectively. Untreated males were placed either in the same tank or in a separate tank that was linked to the injected fish via a recirculation system. The hormonal treatments stimulated spermatogenesis and spermiation in Minj, and ovulation in Finj as well as an increase of the ocular (Io) and gonadosomatic (GSI) indices in both sexes. Plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) increased in Minj and T and 17beta-estradiol (E2) in Finj. A small peak of plasma 17,20beta-dihydroxypregn-4-en-3-one (17,20betaP) occurred during ovulation, while the plasma levels of 17alpha-hydroxypregn-4-ene-3,20-dione (17P) were undetectable in both males and females. The water conditioned by Minj and Finj induced significant, though relatively minor, increases in Io and GSI in uninjected males. In addition, uninjected fish showed small changes in plasma T and 11-KT levels, apparently related to the timing of spermiation and ovulation of Minj and Finj, respectively, as well as an activation of spermatogenesis (but not spermiation). Injected fish released free and conjugated T, 11-KT and E2 into the water, although immature eels were unable to smell (by electro-olfactogram) any of these steroids or prostaglandin F2alpha. However, immature males were highly sensitive to water extracts conditioned by spermiating Minj and pre-ovulatory and ovulated Finj. These preliminary results suggest the existence of chemical communication between maturing eels and immature males that stimulates gonad development, although the putative pheromone(s) involved has/have not yet been identified.

DOI10.1016/j.ygcen.2006.01.017
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/16545383?dopt=Abstract

Alternate JournalGen. Comp. Endocrinol.
PubMed ID16545383
CCMAR Authors