3.4. Morphological analysis
The appearance of this species is characteristic: large, robust body,
ovate or ellipsoidal. Usually, it is not compressed laterally. Specimens
analysed were all sexually mature, and varied between 5.8 cm and 17.3 cm
of length, and 4.1 cm and 9.6 cm of width. Siphons were located in the
anterior part of the body; from 25 specimens only eight had siphons with
different height. Ten specimens had a basal disc. The test, although
hard, is usually quite thin and somewhat soft and flexible, of orange
colour, brown or yellow in live specimens. In fixed specimens, the tunic
was yellowish, brown or grey. Cnemidocarpa verrucosa is
characterized by the presence of warts in the tunic. In this study, some
specimens showed rounded and smooth warts, others presented conic with
multiple spine-like ends warts, and some showed both types distributed
in diverse ways on the tunic with no clear pattern, within the analysed
specimens we found both types of warts. Internal characteristics
represented the intraspecific variation previously described for this
species: branchial sac had four folds in each side of the body, the
number of longitudinal vessels in folds of the branchial sac ranged from
7 to 21, the number of longitudinal vessels between the folds of the
branchial sac ranged from 1 to 5. The oral tentacles are filiform,
alternating in size (short and long), the number ranged from 22 to 38.
The intestine was located on the middle-ventral left side of the body,
there are from 19 to 30 stomach folds. The gonads were tubular, with an
enclosing membrane, and were on the mantle. Specimens showed, in
general, two gonads at each side of the body, nevertheless, specimens
cv12 and cv16 presented two on the right side and one on the left side,
cv23 showed one gonad on each side and cv25 two gonads in the right
side. The distal end with gonoducts was directed toward the atrial
siphon (raw data in https://doi.org/10.1594/PANGAEA.909707).
The NMDS showed two groups among samples (Supplemental information, Fig.
S1). The two groups identified in the NMDS coincided with the specimens
genetically identified as group A and B in the genetic analyses.
PERMANOVA revealed significant differences between the groups conformed
in NMDS analysis (F = 17.17; p = 0.0001). All specimens
from group B showed basal disc, while none of the specimens from group A
did. Almost all individuals from genetic group A had a single type of
wart, while the majority of the individuals from genetic group B had
both types of warts (conical and smooth). None of the other
morphological characters analysed in this study appeared to be
phylogenetically informative.