Close

From Armament to Ornament: Performance Trade-Offs in the Sexual Weaponry of Neotropical Electric Fishes

Kory M. Evans, Maxwell J. Bernt, Matthew A. Kolmann, Kassandra L. Ford, James S. Albert

Posted on: 13 February 2018 , updated on: 19 February 2018

Preprint posted on 11 January 2018

Some electric fishes fence with long jaws for mates! They sacrifice bite force for a longer jaw, which makes a better weapon.

Selected by Cassandra Donatelli

Background: Most of the work on electric fishes has focused on their namesake: the ability to produce electricity. There have been countless studies on their electric organs, communication using electricity, and the role of electricity in navigation and prey capture. However, these fish are more than just their electric organs. They also engage in complex behaviors unrelated to electricity. One such behavior is battling over mates using weapons built in to their faces.

Kory Evans and colleagues discuss the potential consequences of having weaponry used in male contests over mates. They use two species of electric fishes, Apteronotus rostratus and Compsaraia samueli, with elongated jaws as their study system; they are sexually dimorphic, and the elongation of the jaw varies between individuals.

What they did: The researchers took micro-CT scans and created 3D computer models of each individual. They then quantified skull variation using three-dimensional geometric morphometrics. This technique uses anatomical landmarks placed on the 3D models to analyze differences in shape between subsets of a group. Finally, they calculated mechanical advantage of the jaw. Mechanical advantage is an estimate of the force produced by different systems. In this case, the researchers used the relationship between the length of the adductor mandubulae muscle (closes the jaw), and the length of the jaw itself as a proxy for bite force [1].

The discovery: In C. samueli males, the researchers found that fish with longer jaws have a lower mechanical advantage (MA in Fig. 1 below). The relationship is opposite in females, though the variation in jaw length is much lower than in males. In contrast, there was no difference in mechanical advantage between males and females in A. rostraus, and no effect of jaw length on mechanical advantage. The authors conclude that this trade-off between mechanical advantage and jaw length is due to sexual selection. In C. camueli, it may be more important for the fish to have a longer jaw for mating contests than it is for them to produce large amounts of bite force.

Reproduced from Evans et al., Figure 2B

Open questions and possible future studies: It would be interesting to take the study further by measuring the kinematics of the fish during a contest. 3D printed physical models based on the CT scans could also be tested to provide more concrete evidence of mechanical advantage.

[1] Westneat, M.W. 2003 A biomechanical model for analysis of muscle force, power output and lower jaw motion in fishes. Journal of Theoretical Biology 223, 269-281.

Tags: biomechanics, electric fish, fish, sexual dimorphism, sexual selection, weaponry

Read preprint (No Ratings Yet)

Have your say

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up to customise the site to your preferences and to receive alerts

Register here

Also in the animal behavior and cognition category:

Blue appendages and temperature acclimation increase survival during acute heat stress in the upside-down jellyfish, Cassiopea xamachana

Megan E. Maloney, Katherine M. Buckley, Marie E. Strader

Selected by 30 April 2024

Maitri Manjunath

Animal Behavior and Cognition

Experience-dependent plasticity of a highly specific olfactory circuit in Drosophila melanogaster

Benjamin Fabian, Veit Grabe, Rolf G. Beutel, et al.

Selected by 16 February 2024

T. W. Schwanitz

Neuroscience

Behavioral screening of conserved RNA-binding proteins reveals CEY-1/YBX RNA-binding protein dysfunction leads to impairments in memory and cognition

Ashley N Hayden, Katie L Brandel, Paul R Merlau, et al.

Selected by 15 February 2024

Chee Kiang Ewe

Animal Behavior and Cognition

Also in the ecology category:

Blue appendages and temperature acclimation increase survival during acute heat stress in the upside-down jellyfish, Cassiopea xamachana

Megan E. Maloney, Katherine M. Buckley, Marie E. Strader

Selected by 30 April 2024

Maitri Manjunath

Animal Behavior and Cognition

How the liver contributes to stomach warming in the endothermic white shark Carcharodon carcharias

David C. Bernvi, Geremy Cliff

Selected by 22 April 2024

Sarah Young-Veenstra

Physiology

Pervasive sublethal effects of agrochemicals as contributing factors to insect decline

Lautaro Gandara, Richard Jacoby, François Laurent, et al.

Selected by 07 February 2024

Roberto Amadio

Animal Behavior and Cognition

Also in the evolutionary biology category:

Fetal brain response to maternal inflammation requires microglia

Bridget Elaine LaMonica Ostrem, Nuria Dominguez Iturza, Jeffrey Stogsdill, et al.

Selected by 24 April 2024

Manuel Lessi

Neuroscience

How the liver contributes to stomach warming in the endothermic white shark Carcharodon carcharias

David C. Bernvi, Geremy Cliff

Selected by 22 April 2024

Sarah Young-Veenstra

Physiology

A long non-coding RNA at the cortex locus controls adaptive colouration in butterflies

Luca Livraghi, Joseph J. Hanly, Elizabeth Evans, et al.

AND

The ivory lncRNA regulates seasonal color patterns in buckeye butterflies

Richard A. Fandino, Noah K. Brady, Martik Chatterjee, et al.

AND

A micro-RNA drives a 100-million-year adaptive evolution of melanic patterns in butterflies and moths

Shen Tian, Tirtha Das Banerjee, Jocelyn Liang Qi Wee, et al.

Selected by 05 April 2024

Isabella Cisneros

Developmental Biology

Also in the physiology category:

Blue appendages and temperature acclimation increase survival during acute heat stress in the upside-down jellyfish, Cassiopea xamachana

Megan E. Maloney, Katherine M. Buckley, Marie E. Strader

Selected by 30 April 2024

Maitri Manjunath

Animal Behavior and Cognition

How the liver contributes to stomach warming in the endothermic white shark Carcharodon carcharias

David C. Bernvi, Geremy Cliff

Selected by 22 April 2024

Sarah Young-Veenstra

Physiology

Unlocking the secrets of kangaroo locomotor energetics: Postural adaptations underpin increased tendon stress in hopping kangaroos

Lauren H. Thornton, Taylor J.M. Dick, John R. Hutchinson, et al.

Selected by 25 March 2024

EMB EMB_Liv et al.

Zoology

Also in the evolutionary biology category:

‘In preprints’ from Development 2022-2023

A list of the preprints featured in Development's 'In preprints' articles between 2022-2023

 



List by Alex Eve, Katherine Brown

preLights peer support – preprints of interest

This is a preprint repository to organise the preprints and preLights covered through the 'preLights peer support' initiative.

 



List by preLights peer support

EMBO | EMBL Symposium: The organism and its environment

This preList contains preprints discussed during the 'EMBO | EMBL Symposium: The organism and its environment', organised at EMBL Heidelberg, Germany (May 2023).

 



List by Girish Kale

9th International Symposium on the Biology of Vertebrate Sex Determination

This preList contains preprints discussed during the 9th International Symposium on the Biology of Vertebrate Sex Determination. This conference was held in Kona, Hawaii from April 17th to 21st 2023.

 



List by Martin Estermann

EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)

A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.

 



List by Alex Eve

Planar Cell Polarity – PCP

This preList contains preprints about the latest findings on Planar Cell Polarity (PCP) in various model organisms at the molecular, cellular and tissue levels.

 



List by Ana Dorrego-Rivas

TAGC 2020

Preprints recently presented at the virtual Allied Genetics Conference, April 22-26, 2020. #TAGC20

 



List by Maiko Kitaoka et al.

ECFG15 – Fungal biology

Preprints presented at 15th European Conference on Fungal Genetics 17-20 February 2020 Rome

 



List by Hiral Shah

COVID-19 / SARS-CoV-2 preprints

List of important preprints dealing with the ongoing coronavirus outbreak. See http://covidpreprints.com for additional resources and timeline, and https://connect.biorxiv.org/relate/content/181 for full list of bioRxiv and medRxiv preprints on this topic

 



List by Dey Lab, Zhang-He Goh

1

SDB 78th Annual Meeting 2019

A curation of the preprints presented at the SDB meeting in Boston, July 26-30 2019. The preList will be updated throughout the duration of the meeting.

 



List by Alex Eve

Pattern formation during development

The aim of this preList is to integrate results about the mechanisms that govern patterning during development, from genes implicated in the processes to theoritical models of pattern formation in nature.

 



List by Alexa Sadier
Close