2.4. Morphological analysis
A total of 23 specimens assumed to be the putative C. verrucosawere examined for morphological analyses. The samples were dissected,
analysed and photographed using a stereoscopic microscope (Labomed CZM4
and CZM6) equipped with a digital camera for identification and
documentation of internal characters. We analysed the principal external
and internal morphological characters for Cnemidocarpa verrucosa(Lesson, 1830) following established procedures (Millar, 1960; Monniot
& Monniot, 1983; Turon, Cañete, Sellanes, Rocha, & López-legentil,
2016). The external characteristics measured were: 1) position of the
siphons (both terminal siphons on the same line on the distal part, or
one of them oriented towards one side), 2) presence of basal disc, 3)
shape of warts (rounded and smooth, or conical with multiple spine-like
endings), 4) height, and 5) width. After dissection, following internal
structures were noted: 1) number of oral tentacles; 2) total number of
longitudinal vessels in folds of the branchial sac; 3) total number of
longitudinal vessels between the folds of the branchial sac; 4) total
number of gonads (left and right); and 5) number of stomach folds.
Sequencing of COI and 18S markers were carried out for these individuals
in order to test the relationship between genetic and morphological
grouping.