Intraspecific variation in the turtle barnacle, Cylindrolepas sinica Ren, 1980 (Cirripedia, Thoracica, Coronuloidea), with brief notes on habitat selectivity
Author
Hayashi, Ryota
text
ZooKeys
2013
327
35
42
http://dx.doi.org/10.3897/zookeys.327.5732
journal article
http://dx.doi.org/10.3897/zookeys.327.5732
1313-2970-327-35
Cylindrolepas sinica Ren, 1980
Figs 1, 2
Cylindrolepas sinica
Ren, 1980: 194, fig. 6; pl. 2 figs 12-20.
Hayashi 2009
: 1, fig. 1A, B.
Hayashi 2012
: 118, figs 10, 15g, pl. 3d.
Platylepas decorata
Zardus & Balazs, 2007: 1303, figs 7-9.
Frick and Zardus 2010
: 294.
Material examined.
From the plastron of a green sea turtle stranded on Ishigaki Island, Okinawa, Japan, November 25, 2001, Ryota Hayashi coll. (RUMF-ZC-02047); from the plastron of a living green sea turtle, April 17, 2004, Hahajima Island, Ogasawara, Tokyo, Japan, Ryota Hayashi coll. (RUMF-ZC-02045); from a plastic tag on a stranded loggerhead sea turtle, September 26, 2010 at Yomitan, Okinawa, Japan, Ryota Hayashi coll. (RUMF-ZC-02048).
Additional description of intraspecific variation in the parietal wall.
Wall outline stellate, parietes concave (Fig. 1C); translucent between external ornamentation, external
longitudinal
ridges low, broad, poorly defined, growth ridges numerous, fine, closely spaced; (Fig. 1D); sutural elaborations opaque, erect, irregular ridges slightly directed toward apex, not cupped (Fig. 1E); radii very narrow, externally teeth partly concealed
by
sutural elaborations (Fig. 1F); internal midrib broad, short, flaring terminally or club-shaped, directed more downward than medially (Fig. 1G); internal lateral ribs well developed, moderately broad, short, extending below the basal margin, approximately same size and number of ribs on each side of midrib on all plates (Fig. 1
G-H
); sheath about two-thirds height of wall, basally terminating abruptly, not depending (Fig. 1D). Opercular valves and soft parts as described in
Ren (1980)
and
Hayashi (2012)
.
Remarks.
The original description of
Cylindrolepas
sinica
described the rounded, cylindrical form and is accurate for individuals occurring on the soft skin of sea turtles. The general morphology of this species is as described by
Ren (1980)
and
Hayashi (2012)
and illustrated in the present work in Figs 1A, 1B, and 2A.
Frick and Zardus (2010)
and
Frick (2013)
regarded
Cylindrolepas sinica
as a junior synonym of
Platylepas decorata
Darwin, 1854. However, morphological differences between
Cylindrolepas sinica
and
Platylepas decorata
are clearly detailed by
Monroe and Limpus (1979)
,
Ren (1980)
,
Young (1991)
, and
Hayashi (2012)
.
Cylindrolepas sinica
can be distinguished fromother species easily by the morphological characteristics listed in Table 1. In addition, the mitochondrial sequence variation of this and related species has been confirmed (the 12S rRNA, tRNA-Val and 16S rRNA regions, Table 2, see Appendix). Therefore,
Cylindrolepas sinica
is a valid species. In the phylogenetic analysis of
Hayashi et al. (2013)
,
Cylindrolepas sinica
clustered with the whale barnacles (
Xenobalanus
,
Coronula
, and
Cryptolepas
). The pseudo-stalked barnacle
Xenobalanus globicipitis
also has hexagonal and cylindrical shell walls (Fig. 1
A-I
). Comparing these findings,
Cylindrolepas sinica
is likely ancestral to the whale barnacles (
Hayashiet al. 2013
).
Table 1. Comparative features of
Cylindrolepas
spp. and
Platylepas
spp.
| Labrum |
Basal margin of sheath |
Ornamentation of suture |
Longitudinal ridges on parietes |
Radii |
Midrib folds |
Secondary ribs |
Inner surface of parietes |
|
Cylindrolepas sinica
|
|
Cylindrolepas darwiniana
|
|
Platylepas decorata
|
|
Platylepas hexastylos
|
Table 2. List of the materials examined. The GenBank accession numbers are from
Hayashi et al. (2013)
.
| Host animal |
Collected Locality |
Materials deposited number |
GenBank accession numbers |
|
Cylindrolepas sinica
|
Chelonia mydas
|
AB723955 |
|
Cylindrolepas sinica
|
Chelonia mydas
|
AB723954 |
|
Cylindrolepas sinica
|
Chelonia mydas
|
AB723953 |
|
Cylindrolepas darwiniana
|
Caretta caretta
|
AB723959 |
|
Cylindrolepas darwiniana
|
Caretta caretta
|
AB723960 |
|
Platylepas decorata
|
Chelonia mydas
|
AB723950 |
|
Platylepas decorata
|
Chelonia mydas
|
AB723951 |
|
Platylepas decorata
|
Chelonia mydas
|
AB723952 |
|
Platylepas hexastylos
|
Caretta caretta
|
AB723956 |