Back in the 1980s, my lab studied the degree of pre- and postmating
isolation and differences in karyotype between geographical populations of
this "species". We looked at field populations from Connecticut,
Massachusetts, 2 sites in California, and Hawaii. Based on our results this is
a group of species, not one. There are major differences in chromosome
number and chromosome size between New England, California and Hawaii.
You may want to take a look at:
Weinberg, J. R., V. R. Starczak, C. Mueller, G. Pesch and S. Lindsay. 1990.
Divergence between populations of a monogamous polychaete with male
parental care: Premating isolation and chromosome variation. Marine
Biology 107: 205-213.
Weinberg J. R., V. R. Starczak, and D. Jorg. 1992. Evidence for rapid
speciation following a founder event in the laboratory. Evolution 46: 1214-
I recently spoke to Jorge Hardege (I believe he is at U. Hull, UK). In his lab,
he is following up on my work by looking at the mechanism that causes the
worms to have different levels of aggression (which results in pre-mating
isolation in the laboratory between worms from different places). He
indicated that he is collaborating with a geneticist; so there might be some
additional data on relatedness coming soon.
Torkild Bakken wrote:
> According to current usage of genera diagnosis, Nereis includes species
> possessing notopodial homogomph falcigers while species in Neanthes do
> not. The answer to Stan Bosarge's questions should be Neanthes
> arenaceodentata. Having said that, chaetal and parapopodial characters in
> nereidids are highly homoplastic. Robin Wilson and I are in the middle of a
> phylogenetic analysis of nereidids with paragnaths where we will have a closer
> look at this. It is known that most larger genera in Nereidinae are
> heterogeneous, and earlier phylogenetic analyses (e.g. Fitzhugh 1987) give no
> support for treating Neanthes, Hediste, Ceratonereis etc. as subgenera of
>> The species in question, N. arenaceodentata and N. acuminata are very
> similar to N. cricognatha and N. caudata, and has often been treated under one
> name in the literature. I am currently doing a revision of Neanthes, but have
> only examined a few specimens of these species. Specimens labelled N.
> acuminata from North Carolina in the collections of the USNM was identical to
> N. arenaceodentata from Massachusetts (type locality). Specimens of N.
> cricognatha (type locality New Zealand) from Australia are similar but differ
> in paragnath numbers. N. caudata is described from the Mediterranean, as is N.
> acuminata Ehlers(?). They obviously belong to a group of morphological very
> similar taxa, or a complex as Tom Parker said. I would not drop the usage of
> any of these names until type material or topotypic material is examined. It
> would be very interesting to investigate this further using molecular
> analyses. I am very interested in material of these species (under any name),
> both for morphological and molecular studies.
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