Abstract |
Recently, a cephalopod species of the genus Sepioteuthis has entered the Eastern
Mediterranean from the Red Sea, via the Suez Canal. This species, also known as
‘soupiocalamaro’ in Greece, was first recorded off the coast of Turkey in 2002 and it
is, until now, the only Lessepsian squid migrant in the Mediterranean. Based on its
morphological characteristics, previous researchers identified it as Sepioteuthis
lessoniana, a species widely distributed in the Indo-Pacific Ocean and the Red Sea. It
is indicated that S. lessoniana comprises a cryptic species complex, which consists of
multiple distinct genetic clades, with little or no morphological differences. In the Red
Sea, two distinct genetic groups of the species were found, one of which, S. cf.
lessoniana, has a large genetic distance from the previously reported clades. S. cf.
lessoniana was genetically identified with samples collected in Crete, as well. Despite
the particular interest in the S. lessoniana species complex, research has been limited
to its molecular analysis, and there are no morphological descriptions of the individual
genetic clades. Thus, in the present study, S. cf. lessoniana of Crete is morphologically
described and a number of morphometric indices for all Sepioteuthis species are
compared. In addition, elements of the species biology and ecology in the new
environment are studied. For the present work, numerous morphometric and meristic
measurements were taken, while morphometric and biological data were analyzed for
93 individuals of the species collected in Crete. The morphological description of S. cf.
lessoniana was more in line with the already known descriptions of S. lessoniana
species, while the position of the maximum width of the mantle, the number of the
buccal mass’s suckers, and the shape of the fin (only in a few individuals) differed
significantly. Moreover, it is shown that sexual dimorphism in the shape of body
structures occurs, with e.g., females significantly exhibiting greater gladius width than
males. The spawning season seems to last the whole year round with a peak in spring.
Mature individuals were collected during the whole year, while immature ones were
only found in autumn and winter. All males collected in spring were reproductively
mature. The stomach contents were analyzed through metabarcoding using two
barcodes, 16S and CO1. The diet consisted of 9 different species of fish and one species
of ascidians, the majority of which were benthopelagic and common in depths up to
100 m.
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