Greater amberjack

December 10th, 2009

Seriola dumerili, commonly known as the greater amberjack was sighted in Guernsey. This is the first recording of this fish in Guernsey and it is uncommon to Britain. Seriola dumerili are blue or greenish in adults with a silvery white belly and sides. Sometimes, they have a brown or pinkish tinge. The juveniles are between 2 and 17 cm in length and have five dark body bars which split vertically across their body. The maximum recorded size for Seriola dumerili is 188 cm in length although it is common for them to grow up to 110 cm. The greater Amberjack is carnivorous and feed on other fishes and some invertebrates.

Photo of Seriola dumerili here

The goose barnacle, Conchoderma virgatum was also sighted.

Photo: Steve Trewhella

Like this photo? Find out more about this photographer here.

Added by

Six species of barnacle found in Chesil

November 29th, 2009

Six species of barnacle were found in a week of sightings at Chesil. The six species included; the buoy barnacle Dosima faciculalaria, Scalpellum scalpellum and four species of goose barnacle; Lepas anserifera, Lepas hilli, Lepas pectinata and Lepas anatifera.

Dosima fascicularis is also known as the buoy barnacle. Young forms of the buoy barnacle settle on small floating objects in the water such as twigs or feathers, often in groups of about 2-5 juveniles. As they grow, attached to these objects, they produce a white, spongy secretion from cement glands that acts as a float and is similar in texture to polystyrene. Other barnacles can attach to this float and the colony increases in size. Dosima fascicularis is a pedunculate barnacle (has a stalk) which can be pale yellow to purple-brown in colour. Its capitulum can grow up to 30 mm in length.

Another stalked barnacle, Scalpellum scalpellum, attaches to rocks, hydroids, bryozoans etc. It has a flexible muscular peduncle that has an armour of calcareous scales. Its capitulum grows to about 30 mm in height and is usually a white-grey colour with thirteen plates. This is the only shallow water scalpellid barnacle in British waters.

Lepas anatifera is a common goose barnacle. It attaches itself to large floating objects and consists of two parts; the capitulum and the peduncle. The capitulum is about 50mm in length and contains the feeding tentacles and the body of the barnacle. It is oblong in shape and consists of five white plates separated by red-brown or black tissue. The peduncle is a flexible stalk that can grow from 4 up to 85 cm in length! It attaches the barnacle to floating objects.

Lepas pectinata is a small barnacle with a capitulum of only 15 mm. The outer surface or scutum of the barnacle is ridged and it attaches to both small and large objects, such as seaweed. Lepas anserifera is a rare species that is similar to Lepas pectinata but larger with a capitulum up to 40mm long. The barnacle, Lepas hilli is also a rarer species, similar to Lepas anatifera and is distinguished by a paler band between the peduncle and the capitulum.


All photos: Steve Trewhella

Like these photos? Find out more about this photographer here.

Added by

Unusual sightings in July

August 1st, 2007

Despite reduced numbers of sightings this month, perhaps due to the bad weather, there have been some interesting things sighted, including the Dustbin Lid Jellyfish, caught off the Yorkshire coast, a Cuckoo Wrasse sighted in the St Abbs VMCA, a first for the VMCA and a very unusual record for the East coast, and the nationally scarce Glaucus Pimplet anemone, spotted in North Devon.

The dustbin lid jellyfish, Rhizostoma octopus, is usually found on the southern and western coasts of Britain. The jellyfish is solid in appearance and has a dome shaped bell. Its colour varies from a whitish colour to pale shades of green, blue, pink or brown. In mature Rhizostoma octopus, the Gonads (sex organs) for males are blue in colour and reddish-brown in females. Rhizostoma octopus feed on microscopic planktonic organisms and often, the large crustacean Hyperia galba can be found within the body of the jellyfish.

The cuckoo wrasse (Labrus mixtus) is up to 35cm in length for the males and up to 30cm for the females. The functional (older) males are coloured orange-red with a blue striped head and back while non-functional (young) males and females are pink to orange-red with the females having black and white blotches on their lower back.

Glaucus Pimplet (Anthopleura thallia) is a sea anemone that is rare in the UK. The column grows tall, up to 50mm, the anemone varying in colour; green, brown or grey, sometimes with a reddish overcast. The anemone has up to 100 tentacles of moderate length.

The gales in the last week of July also brought in some unusual pelagic species including an unusual form of goose barnacle found in Dorset and North-West Ireland. Has anyone else found anything unusual washed in?

Added by