Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Gobiusculus flavescens

Two spot goby

Two spot goby, Gobiusculus flavescensTwo spot goby, Gobiusculus flavescens
Photos by Andy Rapson

Etymology:

Gobiusculus: Diminutive of Latin, gobius = gudgeon

General Notes:

In many ways the two spot goby is the ideal fish for a native marine aquarium. Unlike most other gobies it is very peaceful and is an active mid water swimmer which usually swims in loose shoals with others of the same species it is always on the go, it remains quite small and is easy to feed. The only drawback being that it is a very short lived species often dying before its second full year. Captive fish with good care may exceed this and live longer due to a regular high quality diet.

Two spot gobies are normally found on the low shore and are not a resident intertidal species and will only tolerate temperatures up to the low twenties centigrade in the long term, higher temperatures will be tolerated in the short term but in captivity a cooler may be required if the aquarium water rises above these levels on a regular basis.

Compatibility:

Very peaceful with other similar sized and peaceful species. May get bullied by larger fish.

Food and feeding:

The wild diet of two spot gobies consists mainly of small crustaceans (copepods, amphipods, mysids), chaetognaths and various larvae. In captivity they will accept a range of suitably sized frozen marine food such as shell fish, chopped krill, mysis shrimps, brine shrimps. Some individuals will learn to accept flake food.

Sexing:

Breeding males can be so brightly coloured with blues and reds that they may appear to be a different species.

Breeding:

Wild G. flavescens breed from June to August under a stone, the male defends the brood until they hatch and then the fry move in to deeper water until the following spring.

The ideal temperature to encourage spawning seems to be around 18°C

A pair may breed in captivity but the fry are tiny and very difficult to raise. Some success may be had if the eggs are moved to a separate aquarium with a simple air powered sponge filter and fed on rotifers as a first food until big enough to accept larger food particles.

Wild status:

The IUCN Red List of endangered species has not evaluated Gobiusculus flavescens. But the species is common across its wide range and is not facing any immediate threats.

Further Information:

If the temperature can be kept below 23°C there will be no need for a cooler. If the temperature rises much above 23°C for extended periods then a cooler will be needed for G. flavescens to thrive.

Information at a glance

pH: 8.2 - 8.4
dGH: 8 - 12
Salinity: 1.021 - 1.025
Temperature: 15 - 23°C (59 - 74°F)
Diet: Omnivore
Size: 6cm (2.4in)
Min tank size: 100 litres
Difficulty level: Easy
Aquarium type: Community
Swimming level: Middle

Distribution and habitat

distribution map for Two spot goby, Gobiusculus flavescens

Origin: Eastern Atlantic: Faeroes, Vesterålen (Norway), and western Baltic to north-west Spain, excluding south-eastern North Sea.

Habitat: Swims close to rocky outcrops or man made structures, beds of seaweed such as Laminaria or Zostera. Very common in rock pools.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Gobiidae
Genus: Gobiusculus
Species: G. flavescens, (Fabricius, 1779)

Other common name:
None

Synonyms:
Gobius flavescens,
Coryphopterus flavescens,
Gobius ruuthensparri