Related Experiment Video
Updated: Jun 1, 2026

Basic Methods for the Study of Reproductive Ecology of Fish in Aquaria
Published on: July 20, 2017
The ovarian structure and mode of egg production in two polygamous pipefishes: a link to mating pattern
1Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan. atsushi-sogabe@hiroshima-u.ac.jp
Abstract:
In this study, the ovarian structure and mode of egg production were examined in two pipefishes, the broad-nosed pipefish Syngnathus typhle and the straight-nosed pipefish Nerophis ophidion, which show different types of polygamous mating patterns. Syngnathus typhle showed an ovary with one germinal ridge and asynchronous egg production, corresponding to previous findings in other polygamous Syngnathus pipefishes. In contrast, the ovary of N. ophidion had two germinal ridges and eggs were produced synchronously in groups, similar to what has been observed in monogamous syngnathids. The egg production of N. ophidion, however, is clearly distinguished from that of monogamous syngnathids by the additional egg production after an ovulation. It is suggested that the differences in female mating strategies result from the difference in egg production process and that this is related to the difference in mating pattern between these two polygamous species.
Related Concept Videos
Fixed Action Patterns
Ovarian Cycle
Oogenesis
Oogenesis
Each primary oocyte is surrounded by a layer of pre-granulosa cells, forming what is known...
Testing a Claim about Population Proportion
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
Mate Choice

