Isles of Scilly Fish and Fisheries - Cornwall Wildlife Trust

in and around the Isles of Scilly since 1996. Two of the females were ovigerous
(berried or egg-bearing).
9.3) Kuruma Prawn Marsupenaeus japonicus
Since 1989 there have been 14 reports (12 after 2000) of jumbo shrimps from the
south west (Dorset to South Wales) and southern Ireland. All those that have been
critically examined have been of the Indo-West Pacific species Marsupenaeus
japonicus (Quigley et al., in press, b). In September 2007 a few jumbo shrimps were
caught in shrimp pots around St Martin’s (K. Lowe, pers. comm. 2009); these may
have been of this species.
M. japonicus is used in aquaculture, being farmed semi-extensively in coastal lagoons,
in the Atlantic Maritime region of France, and it is assumed that these shrimps had
escaped from French facilities, possibly as post-larvae. Specimens have also been
found in the Bay of Biscay. Although all of the specimens appear to have been adults
and there is currently no evidence to suggest that M. japonicus supports a selfsustaining
breeding population in UK or Irish waters (Quigley et al., in press, b).
Similarly there is as yet no evidence of any adverse effects on the local ecosystems
from this non-native species; but it should be noted that in the Eastern Mediterranean
where it is believed to have arrived in the 1920s as a Lessepsian migrant (from the
Red Sea through the Suez Canal) it has almost evicted the previously commercially
important native penaeid prawn Melicertus kerathurus (d’Udekem, 1999).
9.4) Curled Octopus Eledone cirrhosa
Although the Common Octopus Octopus vulgaris probably occurs in the Isles of Scilly,
all recent confirmed reports refer to Eledone cirrhosa, the Lesser or Curled Octopus.
There are occasional records of them throughout the fishing season, but in particular in
October 2009; and in September/October 2010 there were reports of a lot of
octopuses, ranging in size from large adults to smaller juveniles. These appeared to
be entering the pots to feed on the crustaceans within.
E. cirrhosa is a northerly species, which might be expected to decline in southern
areas as a result of climate change, but appears to be doing well in the Isles of Scilly
at present.
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