The Caribbean Roughhead Triplefin
(Enneanectes boehlkei): DNA barcoding reveals
a complex of four West Indian sympatric cryptic species
(Teleostei: Blennioidei: Tripterygiidae)
Benjamin C. Victor
species with distinct DNA lineages and subtle morphological
or marking differences are commonplace among some
reef-fish families, especially the gobies and blennioids.
Often the cryptic species correspond to sets of allopatric
populations in species complexes long recognized by
taxonomists as geographic variants (allospecies).
However, recent large-scale mtDNA sequencing in the
Barcode of Life project has revealed instances of
sympatric cryptic species. This is particularly important
to validate the species-level status of cryptic species
in general, by confirming that barriers to interbreeding
exist and there is no reason to single out some cryptic
species from the spectrum of normal species.
In the case of the Roughhead Triplefin Blenny (the
Enneanectes boehlkei complex), four different
barcode COI mtDNA lineages occur in the Lesser Antilles,
at least three of which can be collected on the same
shoreline on the island of Dominica. When examined
closely, clear marking differences correspond to the
DNA lineages and they are described here as species.
The pairwise sequence divergences (minimum interspecific
distance) among the four species range from 5.6% to
11.8%, on the same order or greater than divergences
among traditional species in the family. The complex
includes both widespread Caribbean species and apparent
endemics to the Lesser Antilles. Enneanectes matador
n. sp. has a red caudal fin, a differently marked
second dorsal fin, and higher fin-ray counts and is
found in the Lesser Antilles and Navassa, as well
as in the W. Caribbean (and probably elsewhere). Enneanectes
wilki n. sp. has a differently marked caudal peduncle
and a dark banded caudal fin and is found only in
the southern Lesser Antilles chain (Windward Islands).
Enneanectes deloachorum n. sp., which also
appears limited to the southeastern Caribbean, has
two dark bars on the rear body, a dark-banded caudal
fin, and higher fin-ray counts. Enneanectes boehlkei
Rosenblatt 1960 has a single prominent dark bar on
the caudal peduncle and a dark-banded caudal fin and
ranges from the Bahamas to the Virgin Islands and
partially down the Lesser Antilles chain, as well
as across the northern Caribbean, including Florida,
and along Central America from Yucatan down to Panama.
An updated key to Western Atlantic triplefins is presented.