4.2 | The Lobata
When the COI phylogeny was limited to the lobate ctenophores,
which form a monophyletic clade (including Thalassocalyce and
Cestids; Podar, 2001), phylogenetic resolution was improved, and theCOI fragment revealed that many genera were polyphyletic (Figure
4b). One example; tropical species of Bolinopsis mikado (Japan),B. vitrea (Bahamas), B. aff. vitrea (Hawaii) andB. ashleyi (Australia) all formed a well-supported clade withMnemiopsis leidyi. The temperate species Bolinopsis
infundibulum (Atlantic Ocean) and a new Bolinopsis MOTU from the
eastern Pacific were in a distinct and well-supported clade (Figure 4b;
and Johnson et al. in prep). This was in contrast to the18S fragment where species within Bolinopsis genus were
undifferentiated, with the exception of a few individuals of B.aff. vitrea collected near Hawaii and Moorea (Figure 4a).
Clearly, more data from more localities, along with transcriptomes and
genomes, are critical in understanding relationships among ctenophores,
but the COI gene provides a useful starting point.
4.3 | Morphological and molecular concordance
Mitochondrial sequencing reinforced the designation of several
undescribed species that returned one 18S MOTU, but differed
morphologically or ecologically (Figure 4). Lampocteis
cruentiventer (Figure 5a) and Lampocteis ‘sp. V’ (Figure 5b),
differed by ~10% GTR distance and were segregated by
depth. A third suspected species within the genus was Lampocteis‘sp. A,’ (Figure 5c) which are typically amber rather than a brilliant
red color, although color is often a misleading trait. However,COI sequences for Lampocteis ‘sp. A,’ differed from the
other two MOTUs by ~17% GTR distance, which gave strong
support for a distinct species.
The COI fragment revealed three distinct Bathocyroe MOTUs
collected from California, and one from the Gulf of California, Mexico,
in contrast to the single MOTU that was returned by the 18Sfragment (Figs. 4a, b, 5d–f). There are three described species within
the genus including B. fosteri (Madin & Harbison 1978) from the
Gulf of Mexico, B. paragaster (Ralph & Kaberry 1950) from the
South Western Pacific, and B. longigula (Horita et al. 2011) from
shallow waters in Japan. Bathocyroe aff. fosteri ‘A’
collected from California most closely matched the description ofB. fosteri (Figure 5d). Bathocyroe aff.longigula (Figure 5f) from California resembled B.
longigula somewhat, in having an elongated stomodaeum, but it
lacked any colored spots along the meridional canals and the gut
appeared wider than that of B. longigula . In addition, theB. aff. longigula from California was mainly found from
~2000–3000 meters depth and B. longigula in
Japan was collected at the surface (although deep species are known to
be occasionally upwelled to the surface in those waters.). In
California, B. aff. longigula and B. aff.fosteri ‘ A’ had overlapping depth ranges, distributions, but had
small distinctions in gut shape (Figure 5d, f) and were the most
divergent from one another molecularly (15% GTR). The third MOTU from
California, Bathocyroe aff. fosteri ‘B’, had a distinct
gut shape and color from all the other MOTUs, was relatively rare, and
was only collected below 3000 meters depth (Figure 5e). Unfortunately,
specimens from type localities were unavailable for sequencing so it is
unclear if any of the MOTUs we sequenced match those already described
or new to science. However, with our new primers researchers world-wide
can now amplify species of Bathocyroe and help to confirm species
identifications.
The COI fragment sequences also resolved the
relationships between Deiopea kaloktenota (Chun 1880) andKiyohimea usagi (Matsumoto & Robison 1992). It was first
suspected that despite morphological distinctions, Deiopea might
be a juvenile form of Kiyohimea (Matsumoto & Robison 1992). By
sequencing the COI fragment we found two distinct lineages ofDeiopea from California in addition to that of K. usagi. A
single specimen collected offshore of the Hawaiian Islands also was the
same MOTU as one of the Deiopea from California, showing this
species has high dispersal capabilities and a broad oceanic
distribution. Specimens of D. kaloktenota, which were described
from the N. Atlantic, and K. aurita (Komai & Tokioka 1940) from
Japan were unavailable for sequencing, so it is unclear whether one or
both species of Deiopea from Monterey Bay are undescribed.