Breeding: Spring. The male
builds a nest and guards it. See below.
Habitat: Shallow seas, estuaries,
brackish to only 5 metres depth.Occasionally in tide pools.
Food: Small crustaceans, live food
only. In aquaria this fish will nip the fins of other fish and this behaviour
has been observed in the wild, but it is not common.
British coasts but not much further afield.
- Biscay, Baltic.
(by the late Chris Batt
of "Silent World" Aquarium, Tenby, SW Wales).
The only truly marine stickleback, this
small fish, which normally reaches a maximum length of 150 mm, is probably
the most attractive of the stickleback family. In breeding condition the
male has a brown chequered pattern consisting of brown vertical bars alternating
with silvery-yellow ones along the lateral line with a silvery-yellow underside
whilst the female is much brassier yellow all over, with fewer vertical
bars and is somewhat heavier in build. If gravid the female is easily recognisable
by her sheer bulk. Both sexes may (or may not) have dorsal and ventral
fin patterning. Freshly captured fish will normally only take only live
food (small shrimp, Mysid, freshwater insect larvae, Daphnia, Gammarus),
indeed, they may refuse food altogether. However, once settled, ours took
frozen Mysid readily. These fish need a tank with plenty of cover - rocks
or seaweeds or even (ugh!) plastic plants. They do not tolerate
high nitrates and need high water quality generally, although we have kept
them in water temperatures of up to 20° C.
We had a male all winter, in our "Gelliswick
Bay" tank, which had started nest-building on 15th March. The completed
nest was about 100 mm from the bottom, amongst a clump of Chondrus
crispus seaweed and really consisted of nothing but bundled-up
seaweed fronds, which were securely tied up with silk-like threads produced
by the male's kidneys. We needed a female!
Netting through kelp during an extreme low
spring tide in Gelliswick Bay, Milford Haven on 21st March, Jim Hall and
I caught about thirty of these fish (mostly males)- indeed they were the
most frequently found fish, with Corkwing Wrasse,
melops, coming a close second. We selected about ten to take home and
released the rest. I really only needed a couple of females but I thought
that territorial behaviour might be interesting so I thought an extra male
would also be useful. At this stage we were unsure of how to sex the fish
but I picked out four of the plumpest ones and installed them in our tank,
along with another male. To allow the fish to settle down, the lights were
turned off and the tank was left alone.
Next morning, we found that all of the new
fish were being harrassed by the resident male and were, when not being
chased, hiding in a vertical position (in both head- and tail-down positions!)
in the corners of the tank and behind rocks, pretending to be bits of seaweed.
No sign of eggs could be seen in the nest (although there may have been
some in it). This behaviour continued for some days (one fish jumped out
through a 2 cm gap in the glass cover). The "new" fish all sustained damage
to the narrow caudal area and the tail-fin. There was no attempt at nest-building
by the other male.
I subsequently removed three of the new
fish, including the male, and installed them in our "touch-tank" which
is larger, has plenty of cover and has a shallow "beach" area where fish
can hide. The male started nest-building within three days and began to
harass the other two fish. I supposed that these were also males (or females
that had already laid) so asked Jim Hall if
he would swap two of his fat females for some of mine. He brought
these on 11th April. The remaining two females were taken from the original
tank and one new gravid one was installed in this tank and two in the touch-tank.
Over the following few days it was noticed that the new females were treated
much less aggressively than the others had been and would make advances
toward the male by shimmying at broadside to him. We did not see the males
trying to attract females to the nest.
A clump of about 30 small white eggs (each
about 1 mm diam.) was noticed on 13th April in the "Gelliswick Bay" tank.
The male was fanning these with his pectoral fins and had added new materials
to the nest. The female was being kept well away from the nest now and
was behaving exactly as he other fish had done. Several days later she
also sustained damage to the caudal area and was removed. The male continued
to defend the nest agains all-comers, including a juvenile Common Cuttle,
vulgaris, of about 100 mm length and much greater bulk than the stickleback.
The nest in the touch-tank was also guarded
assiduously by the male. Other sticklebacks as far away as 1.4 m were harassedand
all other fish, including much larger blennies,
were kept well away by frenzied ramming attacks.(No evidence of use of
the dorsal spines was seen as reported by other writers).
9 May 2012
I caught a 5lb+ bass in the Menai Straits Anglesey. I would
have returned a fish of this size but it had swallowed the bait so decided
to eat this one. As I emptied the stomach I found a fish 15 cm long. As
I did not know what this fish was I put it in bag and put it in the freezer.
On my way home I called in at Anglesey bait centre and they told me it
was a stickleback.
Information wanted: Please send any records of this fish, with
location, date, who discovered it, how it was identified, prevalence, common
name and any other details to
All messages will receive a reply.
Project EMail Glaucus@hotmail.com.