Quadrimaera sp., not Quadrimaera inaequipes - A maerid amphipod (Amphipod images)

Specimen 1 -
Adult male

Specimen 2 -
An adult berried female

Maerid amphipod
Quadrimaera species
- lateral view female 1

Maerid amphipod
Quadrimaera species
- lateral view anterior female 1

Maerid amphipod
Quadrimaera species
- lateral view anterior female 2

Maerid amphipod
Quadrimaera species
- lateral view posterior female 1

Maerid amphipod
Quadrimaera species
- lateral view posterior female 2

Maerid amphipod
Quadrimaera species
- gnathopod 2 female 1

Maerid amphipod
Quadrimaera species
- lateral view female 2

Maerid amphipod
Quadrimaera species
- female / 0.1mm division rule 1

Sub-adult females

Maerid amphipod
Quadrimaera species
- telson sub-adult female under microscope 1

Maerid amphipod
Quadrimaera species
- telson of slightly younger female than above 1

Habit and location

Maerid amphipod
Quadrimaera species
- shallow sublittoral habitat with Saccorhiza polyschides and Laminaria hyperborea 1

Maerid amphipod
Quadrimaera species
- shallow sublittoral habitat with Saccorhiza polyschides and Laminaria hyperborea 2

Maerid amphipod
Quadrimaera species
- location / Battery Rocks, Penzance, Cornwall, UK 1

The specimens above were found by the author, on washing the holdfasts of Saccorhiza polyschides, Furbelows, collected from a shallow sublittoral gulley at Battery Rocks, Penzance, Cornwall, 20.09.20.

Specimens were gathered on the 20.09.20 and 21.09.20, the latter after identification of Quadrimaera. Approximately 50 specimens were found over the two days, most were juveniles. There were few adult specimens and only one berried female.

This species here appears to be a new, potentially invasive non-native species for the UK. Quadrimaera species are incredibly difficult to identify and there may even be as many as three species of Quadrimaera present on coastlines of the English Channel, one so far in the UK, but the species are likely to share similar habitat i.e. lower littoral to shallow sublittoral rocky shores with large brown algae such as Laminaria and Saccorhiza. It may take some time to identify the species present here in the UK. There is a chance it could be a new cryptic species or indeed a hybrid that has formed as a result of bioinvasion we just don't know yet.

My thanks go to Dr. Jessika Alves, Universidade Federal da Bahia, Brazil, and Dr. Lauren Hughes at the Natural History Museum, London, for the help they have given so far, the research continues.

To date the author has also found Quadrimaera sp. at Long Rock reef, Penzance on 30.03.21 and at Albert Pier reef, Penzance on 31.03.21, on both occasions near low water on extreme low tides and associated with holdfasts of the brown alga Saccorhiza. This species is likely more widespread across the south coast of Cornwall, however the species has only recently turned up in samples on washing Saccorhiza holdfasts. It must be noted that the species appears associated with both juvenile

APHOTOMARINE

An educational resource dedicated mainly to the photography
and diversity of marine life that can be found in coastal waters
and intertidal areas of Great Britain and Ireland by David Fenwick.

APHOTOMARINE

An educational resource dedicated mainly to the photography and diversity of marine life that can be found in coastal waters and intertidal areas of Great Britain and Ireland by David Fenwick.

An educational resource dedicated mainly to the photography
and diversity of marine life that can be found in coastal waters
and intertidal areas of Great Britain and Ireland by David Fenwick.