# Environmental and Physiological Regulation of Reproduction in the Goldfish: Gonadal Development, Maturation, and Spawning Behavior: A Review

## TL;DR

This paper reviews how goldfish reproduction is regulated by hormones and environmental factors, highlighting its importance as a model for studying fish biology and conservation.

## Contribution

The paper provides a comprehensive review of goldfish as a model for understanding fish reproduction, emphasizing hormonal pheromones and endocrine regulation.

## Key findings

- Goldfish release hormones into water that act as pheromones to coordinate spawning behavior.
- The goldfish's endocrine system regulates gonadal maturation and sexual behavior through hormones like 11-ketotestosterone.
- Goldfish studies have improved understanding of fish neurobiology, toxicology, and conservation.

## Abstract

This paper critically reviews the physiological and ecological processes that regulate reproduction in the goldfish, one of the best understood models amongst the fishes. First, we describe how hormonal changes driven by ecological variables are known to be responsible for gonadal maturation and reproductive behavior—and how this applies to other species. Next, we describe how and why goldfish release hormones to the water to function as potent pheromones which mediating many aspects of male–female behavior. Finally, endocrine determinants of sexuality are reviewed. We show how the relatively large body size of this species, its close relationship to many other important species, and the ease with which it can be maintained make it ideal for studies on comparative endocrinology, toxicology, chemical ecology, fisheries management and conservation.

The goldfish, a member of the Cyprinidae (minnow family) is an important and relevant model for understanding how fish function and reproduce and can be better managed. Here, we review recent studies of this species and its strengths as a model system. First, we review current understanding of how its neuroendocrine system regulates gonadotropin release, and then steroidogenesis and finally gonadal maturation in both males and females. Endocrine determinants of gender and sexual plasticity are described. Effects of the fish androgen, 11-ketotestosterone, on sexual and spawning behavior of males and females are reviewed. We also describe how several hormones (androstenedione, 17,20β-dihydroxy-4-pregen-3-one, prostaglandin F2α) and their metabolites function as “hormonal pheromones” to synchronize male–female spawning behavior and physiology. Insight provided by the goldfish has enhanced understanding of the neurobiology, toxicology, and comparative physiology of other fishes and provided lessons applicable to the culture of commercial carp and the control of invasive species, as well as conservation.