Functions of bidirectional sex change and simultaneously hermaphroditic phase gonads in the monogamous goby Lubricogobius exiguus

Hermaphroditism has been widely confirmed in fish and includes four recognized types: protogyny, protandry, bidirectional sex change, and simultaneous hermaphroditism. Among these, bidirectional sex change and simultaneous hermaphroditism are considered the most flexible sexual patterns, due to their frequent switching of functional sexes. They are predicted to evolve under conditions of limited mating opportunities, such as low population density and mobility, and are thought to share common evolutionary factors. The goby Lubricogobius exiguus exhibits bidirectional sex change, with simultaneously hermaphroditic (SH) phase gonads, containing both developed testicular and ovarian tissues, particularly in females and solitary individuals. In this study, we conducted field observations to examine the mating system in L. exiguus and investigate the significance of its plastic sexual patterns. The results revealed that the goby randomly formed mating pairs, regardless of body size. Although..., , # Functions of bidirectional sex change and simultaneously hermaphroditic phase gonads in the monogamous goby *Lubricogobius exiguus*

Dataset DOI: [10.5061/dryad.pc866t21v](10.5061/dryad.pc866t21v)

## Description of the data and file structure

### FILE Data breeding pair.csv 

OVERALL DESCRIPTION:

This file contains the data of breeding pairs in Lubricogobius exiguus.

COLUMN EXPLANATION

* Pair ID: \"Identification number of the breeding pair\"
* Number of spawning: \"Number of spawning observed in this study\"
* Pair period: \"Pairing period in each pair (day)\"
* Male ID: \"Identification number of male individual\"
* Female ID: \"Identification number of female individual\"
* Male TL: \"Total length of male individual (mm)\"
* Female TL: \"Total length of female individual (mm)\"
* Size difference: \"Absolute difference in total length between males and females in each pairs (mm)\"
* Observation type: \"Types of observed cases for each pair. F represents the entire observed pairing period, while...,