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Gobies and how to identify
them
Introduction
There
are lots of gobies which can be found in rockpools and
shallow sea but they can look very similar at a glance
so making a positive identification can be quite
difficult. Even the type of environment can be used to
help differentiate some species from other very similar
species, large black gobies (Gobius niger) for
example can look very similar to sub adult giant gobies
(Gobius cobitis). Most gobies are extremely
variable in colour too which further complicates things.
Gobies can be recognised from their
quite similar relatives the blennies quite easily by
looking closely at some of their characteristics.
Gobies have two separate dorsal fins where blennies have
a single dorsal fins which runs along most of their
backs. Gobies have a fused pelvic fin where blennies
have two separate pelvic fins and in most cases blennies
have cirri which are ornate growths above each eye,
On the left is a goby and on the right a blenny.
Fin rays key:
D1 = the first dorsal fin; D2
= The second dorsal fin; A = The anal
fin; P = Pectoral fin.
Numbers are used for soft rays and
Roman numerals are used for stiff rays
Gobies which are found in the
UK
Two spot goby,
Gobiusculus flavescens
The first two fish pictured above are
of the very same fish and taken just two day apart. This
first photo was taken immediately after capture and the
second photo after the fish had been in our aquarium for
48 hours it shows just how variable gobies can be in
different environments. The third photo is of a wild two
spot goby in a rock pool.
Key features:
Fin rays: D1: VII (VII - VIII);
D2: I + 9 - 10; A: I + 9 - 10; P: 17 - 18;
Length: 6 cms.
Colour
features: Large black spot below the first
dorsal and another at the base of the tail.
Habitat: Shallow water among rocks and weed,
unusually for a goby they spend most of their time
swimming in mid water.
Two spot gobies are common along the
south and west coast line but less common along the east
coast of the UK. They breed from spring to late summer.
It is unlikely that these gobies could be mistaken for
another.
Painted goby,
Pomatoschistus
pictus
Key features:
Fin rays: D1: VI (V - VII); D2: I
+ 9 (7 - 10); A: I + 8 - 9; P: 18 - 19 (16 -
20);
Length: 5.7 cms.
Colour features: One or two rows of spots on
the first dorsal.
Habitat: Inshore
and down to 50m, over sand or gravel.
Painted gobies are found all around
the UK but seem to be most common along the south coast.
They are extremely well camouflaged in their natural
habitat as can be seen in the photos. Painted gobies are
a bottom living species and rarely swim mid water.
Rock goby,
Gobius paganellus
Key features:
Fin rays: Dl: VI; D2: I + 13 - 14
(12 - 15); A: I + 11 - 12 (10 - 13); P: 21 -
22 (18 - 23);
Length: 12 cms.
Colour features: The colour is
extremely variable but there is a band of cream to red
along the top edge of the first dorsal.
Habitat: Inter tidal under stones, and in weedy
rock pools.
Rock gobies are most common on the
south coast but can be found all around the UK where
there is suitable habitat. Rock gobies are relatively
large gobies but they are easy to identify using the
band of colour along the top edge of the first dorsal.
Occasionally this band of colour is quite pale and may
go unnoticed the fish may then be confused with both
Gobius niger and Gobius cobitis.
Giant goby,
Gobius cobitis
Key features:
Fin rays: Dl: VI; D2: I + 13 (13
- 14); A: I + 11 (10 - 12); P: 20 - 21 (19 -
22);
Length: 27 cms.
Colour features: Breeding males are dark with
white edges to unpaired fins.
Habitat:
Sheltered rock pools with stones and weed cover. Giant
gobies can be found high up the intertidal zone.
Giant gobies as their name suggests
are large gobies and adults cannot be mistaken for any
other goby. Juveniles are very similar to both rock
gobies and black gobies.
They are only found very
rarely and only on parts of the south coast. The south
coast of the UK represents the most northerly part of
their natural range. Giant gobies are a protected
species and it is illegal to catch, harm or even disturb
one with a maximum penalty of six months in prison.
Common goby,
Pomatoschistus microps
Key features:
Fin rays: Dl: VI (V - VII); D2: I
+ 89 (8 - 11); A I: + 8 - 9 (7 - 10); P: 17
- 19 (15 - 20);
Length: 6.4 cms.
Colour features: Males have up to 10
vertical bars on their flanks, males also have a dark
spot to the rear of D1.
Habitat:
Inshore, found in pools right up to the high tide mark,
and locked lagoons, salt marshes, and estuaries. They
are found out in the open over sand or mud and in rocky
weedy areas too.
Common gobies can easily be mistaken
for sand gobies. Sand gobies tend to be less transparent
and have a more solid colour. They are common all around
the UK.
Sand goby, Pomatoschistus
minutus
Key features:
Fin rays: Dl: VI (VI - VII); D2:
I + 10 - 12; A I + 9 - 12; P 18 - 2;
Length: 9.5 cms.
Colour
features: Four vertical bars present on both
sexes and dark wedge shaped spot to the rear of D1
present on both sexes.
Habitat: In
shore over sand and mud.
Sand gobies are common all around the
UK
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