Social rank modulates brain arginine vasotocin immunoreactivity in false clown anemonefish (Amphiprion ocellaris)

Abstract

The brain nanopeptide arginine vasotocin (AVT) and its mammalian homolog arginine vasopressin are involved in the regulation of social and reproductive behavior. We investigated the relationship between social rank formation and the brain AVT system in the false clown anemonefish (Amphiprion ocellaris), which forms a social rank that leads to sex differentiation in higher-ranked individuals. Tanks of three sexually immature fish were kept for 90 days and each fish's behavior was observed once a month. The social rank of each individual was distinguishable by behavior, but gonadosomatic index (GSI) did not differ significantly. The number of AVT neurons in the magnocellular layer in the preoptic area (POA) increased in subordinate individuals and declined with increasing hierarchical dominance. These results suggest that social rank formation modulates AVT production in the brain of the clown anemonefish and may influence their later sex differentiation.

Brain Arginine Vasotocin Immunoreactivity Differs between Urban and Desert Curve-Billed Thrashers, <i>Toxostoma curvirostre</i>: Relationships with Territoriality and Stress Physiology

“…However, such species-specific differences in the effects of AVT on aggression likely result from the use of different behavioral testing methods and not opposing responses to AVT in the lateral septum . Varying relationships between neural AVT and aggression (or specific dominant vs. subordinate phenotypes) have also been reported in fish and reptiles [Larson et al, 2005;Lema, 2006;Ohya and Hayashi, 2006;Santangelo and Bass, 2006;Dewan et al, 2008;Greenwood et al, 2008;Hattori and Wilczynski, 2009;Iwata et al, 2010]. Collectively, these studies highlight the complexity of AVP/AVT's role in aggression and how this evolutionarily conserved system can contribute to context-specific behavioral responses.…”

The distribution of an AVT V1a receptor in the brain of a sex changing fish, Epinephelus adscensionis

“…This difference has been documented in several species of sex changing fish such as wrasse, goby, and anemone fish where sex specific behavior has been correlated with AVT cell populations in the POAH that vary in relation to sexual state (Godwin et al, 2000;Grober and Sunobe, 1996;Iwata et al, 2008). The AVT V1a type receptor has been implicated in the control of certain male behaviors in different vertebrate groups because administration of an AVP V1a specific antagonist can disrupt these behaviors.…”

Immunohistochemistry of Brain Arginine Vasotocin and Isotocin in False Clown Anemonefish Amphiprion ocellaris~!2009-12-08~!2010-04-14~!2010-06-29~!

“…An observable relationship between body mass and the number and size of AVT and IT-ir neurons was not evident. Our previous study [5] indicated that the number and size of AVT-ir neurons in the POA were notably influenced by body mass after 90 days of pairing, and the results with mass-corrected data showed that the number of AVT-ir neurons in the magnocellular layer declined with increasing hierarchical dominance. This contradicts our present results, which show the same trend with or without mass correction (data not shown).…”

“…Preadsorption tests on anti-AVT and anti-IT sera were omitted because their specificity had already been verified [5,[7][8][9][10].…”

“…Our previous study revealed that 90 days after group formation false clown anemonefish Amphiprion ocellaris (Cuvier, 1830) had different brain AVT phenotypes according to their social rank [5]. The relationship between AVT and IT, however, is still unclear, as is the involvement of these peptides in the social behavior of anemonefish.…”