Nasoecia nasotuberculata (Müller, G.W., 1906)
Records: 142
This is a small shallow mesopelagic species that is characterized by its globular shape, the right
asymmetrical gland opening very close to the tip of the rostrum, and the development of lateral tubercles
at the posterior dorsal corner, particularly in the female. Even so, the mislabelling of Muller's (1906)
original illustrations lead to its confusion with M. kyrtophora (Angel, 1981). Its apparent absence
from some regions may be a result of this confusion. It was originally described as a Conchoecia
species in Müller's 'rotundata group', and as such it was re-classified as a Metaconchoecia
species by Poulsen (1973). Recently the genus Metaconchoecia has been substantially revised by
Chavtur and Angel (in press). Recognizing that the old concept was very heterogeneous, while being clearly
separated from other halocyprids by the locations of the symmetrical glands, they have established a tribe,
the Metaconchoeciinae, and divided the species into ten genera, while still retaining the genus
Metaconchoecia. The unique features of this species result in its classification in a new
monospecific genus.
In the North Atlantic it seldom spreads north of 30°N, but in the South Atlantic it crosses the Subtropical
Front, and to the south of Australia its range extends almost to the Subantarctic Front. Such a disjunct
distribution suggests that this species should be further examined to see if there are cryptic species.
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