| Full text | |
| Author(s): |
Total Authors: 2
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| Affiliation: | [1] Univ Sao Paulo, Inst Biosci, Dept Zool, Rua Matao, Travessa 14, Sao Paulo 05508090, SP - Brazil
Total Affiliations: 1
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| Document type: | Journal article |
| Source: | BULLETIN OF MARINE SCIENCE; v. 96, n. 2, SI, p. 375-398, APR 2020. |
| Web of Science Citations: | 1 |
| Abstract | |
Cephalopods are a remarkable group for studies on sexual selection, due to their complex reproductive behavior, pronounced sexual dimorphism, polygamous behavior, as well as cumulative evidence of pre- and postcopulatory male-male competition and female choice in the group. This paper provides a review of sexual selection studies on cephalopods, with an emphasis on the loliginid squid mating system. In this system, males may adopt alternative reproductive tactics (ART) and display male intrasexual dimorphism, with each morph generally exhibiting distinct behaviors and ejaculate traits. Consort males typically transfer ejaculates to the female mantle cavity, while sneaker males typically transfer ejaculates to the female buccal region, where a sperm storage organ is located. Each site provides distinct fertilization environments for the ejaculates of each morph, differing in the availability of eggs, gamete protection, and timing between mating and fertilization. Accordingly, the ejaculates of each morph show putative adaptations for each site, differing in size, morphology, sperm release duration, and sperm behavior. Although solid evidence is lacking for most loliginids, cryptic female choice may occur in this system through, for example, spermatangia removal or egg string manipulation during fertilization. In addition, recent evidence for one loliginid species indicates that adoption of male ART is ontogenetic and may represent two alternative pathways: from immature males (i) directly to consort phenotype or (ii) going through a sneaker phase, then switching to consort morph. The second pathway would, therefore, imply striking change in behavior, physiology, and ejaculates. Moreover, data on the age of this species suggests that the adoption of sneaker tactic early in life may be associated with extending the male mating period by 25%. With such a peculiar system, loliginids should prove useful not only for comprehending the evolution of female promiscuity and ART in cephalopods, but also as an emerging nonvertebrate and nonarthropod model for testing sperm competition models. (AU) | |
| FAPESP's process: | 13/02653-1 - Evolution of sperm transfer mechanisms in cephalopods: adaptative convergences associated with habitat shifts in the marine environment? |
| Grantee: | José Eduardo Amoroso Rodriguez Marian |
| Support type: | Scholarships in Brazil - Post-Doctorate |
| FAPESP's process: | 15/15447-6 - Unraveling post-copulatory sexual selection mechanisms in cephalopods: morphology of the squid's seminal receptacle applying Confocal Microscopy and 3D Reconstruction |
| Grantee: | Luiza de Oliveira Saad |
| Support type: | Scholarships abroad - Research Internship - Master's degree |
| FAPESP's process: | 17/16182-1 - Post-copulatory sexual selection in a squid (Mollusca: Cephalopoda) with male intrasexual dimorphism and two fertilization sites |
| Grantee: | Lígia Haselmann Apostólico |
| Support type: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 18/19180-2 - Cephalopod International Advisory Council Conference |
| Grantee: | José Eduardo Amoroso Rodriguez Marian |
| Support type: | Research Grants - Meeting - Abroad |
| FAPESP's process: | 14/11008-5 - Function and evolution of the seminal receptacle in Decapodiformes (Mollusca: Cephalopoda): unraveling postcopulatory sexual selection mechanisms in cephalopods |
| Grantee: | Luiza de Oliveira Saad |
| Support type: | Scholarships in Brazil - Master |