Social promiscuity in field populations of
Hippocampus
abdominalis
We observed courtship behaviour on a total of eight
occasions across the three field sites (Table 2). In all cases,
we observed groups of females with a single male who
invariably displayed colour changes, pouch pumping
and jackknifing (Table 2). When we had the opportunity
for extended observations, we usually saw other courtship
behaviours including pointing and promenading, and on
five occasions, we observed female–female interference
whereby one female would swim between a displaying
male–female pair and attempt to initiate display or a
displaying female would ‘guard’ a male. In order not
to disrupt courtship behaviour, we could not measure the
size of seahorses involved but on all occasions we observed
longer periods of courtship with the largest females in
the group. Male seahorses would often display with one
particular female, display with one or more others and
then return to display with the original female. We did not
observe rising in the water column and egg transfer.