Gobius couchi

Researched By	Karen Riley	Data Supplied By	MarLIN
Refereed by	Prof. Robert Patzner
Taxonomy
Scientific name	Gobius couchi	Common name	Couch's goby
MCS Code	ZG464	Recent Synonyms	None
Phylum	Chordata	Subphylum	Vertebrata
Superclass	Gnathostomata	Class	Osteichthyes
Subclass	Teleostei	Order	Perciformes
Suborder		Family	Gobiidae
Genus	Gobius	Species	couchi
Subspecies
Additional Information	Couch's goby is a very localised, rare and protected species. It is found low shore under red or green algae in south Cornwall and north west Ireland, below high tide level in County Cork and sublittorally in a sheltered sea lough in south Ireland.
Taxonomy References	Hayward & Ryland, 1995b, Wheeler, 1994, Froese & Pauly, 2000(b)
General Biology
Growth form	Pisciform	Feeding method	Omnivore
Mobility/Movement	Swimmer	Environmental position	Demersal
Typical food types	Algae, crustaceans, bivalves and polychaetes.	Habit	Free living
Bioturbator		Flexibility	High (>45 degrees)
Fragility	Intermediate	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	Insufficient information
Adult dispersal potential	No information found	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	Gobius couchi is a rare British marine fish which feeds on algae, crustaceans, bivalves and polychaetes. It is known to reach a maximum of 9 cm in length and has a life span of approximately 6 years.
Biology References	Hayward & Ryland, 1995b, Wheeler, 1994
Distribution and Habitat
Distribution in Britain & Ireland	This species has only been recorded from four locations in the British Isles: Helford in south Cornwall; Bill of Portland, Dorset; Lough Hyne, Co. Cork, Ireland; and Mulroy Bay, Co. Donegal, Ireland.
Global distribution	Couch's goby has recently been recorded at Naples in the western Mediterranean and in the Adriatic Sea.
Biogeographic range	Not researched	Depth range	0.5 to 16 m
Migratory	Non-migratory / Resident
Distribution Additional Information	Gobius couchi was discovered relatively recently, in 1974, and is considered to be a resident of three locations in the British Isles. However, it was recorded in 1998 in the western Mediterranean (Ischia Island, Naples, Italy) (Stefanni & Mazzoldi, 1999), and, more recently, in the Kvarner region of the Adriatic Sea (Kovacic, 2001) suggesting that the distribution of the species may be wider. Couch's goby occurs in fully saline water. Both Irish localities where the goby is found are sheltered and have reduced tidal ranges (Minchin, 1988). At Lough Hyne and Mulroy bay there are well-established populations. Couch's goby ranges in depth from 0.5 to 16 m at Lough Hyne and 3-14 m depths at Mulroy bay (Minchin, 1987). It tends to be found with stones in shallow water, boulders at greater depths and also with shell debris. Gobius couchi was noted to be the most dominant species present in some areas. Helford is a sheltered, land-locked habitat. In this environment Gobius couchi is normally associated with flat stones or muddy sand with shells and pebbles present (Minchin, 1988). They are also exposed at low water spring tides. Potts & Swaby (1991) observed that the population at this site has diminished over the last 10 years. The salinity preferences of Gobius couchi lie between 25-35 psu.
Substratum preferences	Pebbles, Mixed, Rockpools, Under boulders, Maerl, Fine clean sand, Muddy sand, Sandy mud, Mud	Physiographic preferences	Open coast, Enclosed coast / Embayment
Biological zone	Sublittoral Fringe	Wave exposure	Sheltered
Tidal stream strength/Water flow	Insufficient information	Salinity	Variable (18-40 psu)
Habitat Additional Information
Distribution References	Wheeler, 1994, Stefanni & Mazzoldi, 1999, Minchin, 1987, Minchin, 1988, Potts & Swaby, 1991, Eno et al., 1997, JNCC, 1999, NBN, 2002, Kovacic, 2001
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Oviparous
Reproductive Season	Spring and summer	Reproductive Location	Insufficient information
Reproductive frequency	Annual protracted	Regeneration potential	No
Life span	See additional information	Age at reproductive maturity	Insufficient information
Generation time	Insufficient information	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	External
Larvae/Juveniles Larval/Juvenile dispersal potential 1km-10km Larval settlement period Insufficient information Duration of larval stage Insufficient information
Additional Information	Gobius couchi has a life span of up to 6 years (Miller, 1986). Very little information is available detailing the reproduction of Gobius couchi, but it is probable that this is fairly similar to that of other Gobiidae. For instance, Gobius cobitis, Pomatoschistus microps, and Pomatoschistus minutus usually produce 2 clutches of eggs each breeding season. Eggs are laid by the female and attached to the under-surface of large boulders or shells. The eggs are then fertilized and guarded by the male. Thus the eggs are protected and kept inshore until the feeding larvae hatch. The breeding season usually occurs in spring and early summer in Britain. Fecundity will probably vary between 2,000 and 12,000, within the same range as that of other Gobiidae.
Reproduction References	Potts & Swaby, 1992, Miller, 1986