An Updated Classification of the Recent Crustacea

DECAPODA: CARIDEA
I of course must strongly disagree with the proposed
arrangement of the caridean families into superfamilies,
because I see this as a retrocess from
taxa sustained by apomorphic characters (Christoffersen,
1990) back to groupings based on overall
resemblance, authority (Chace, 1992; Holthuis,
1993), or arbitrary usage. It is true that my proposals
have had little following in the carcinological
community, and that some of my employed
characters may be questionable. But it is also true
that my efforts remain the first attempt to produce
a phylogenetic system of the Caridea. Because my
system differs substantially from the traditional arrangements,
my suggestions have usually been dismissed
as totally heretical, without any serious attempt
to argue alternative possibilities sustained by
better uniquely shared characters. It is rather depressing
to note that the present authors follow this
same tactic. They do not accept a single superfamily
as synthesized in Christoffersen (1990). More
explicitly, but without justification, they reject my
proposal to combine alpheoids, crangonoids and
pandaloids into a monophyletic taxon. This is surprising
to me, because these superfamilies, as redefined
in my cited works, share a remarkable synapomorphy,
the multiarticulated carpus of the second
pereiopod, which is a unique adaptation within
the carideans for body cleaning. For this transformation
series, there is even a transitional stage represented
by the nematocarcinoids, in which the carpus
of the second pereiopods is longer than in the
preceding carideans, before being subdivided in the
sister group represented by pandaloids, crangonoids,
and alpheoids. At a still higher level of generality,
this transformation series is congruent with
the presence of a well developed incisor process on
the mandible of palaemonoids and all the previously
mentioned superfamilies. Going to a lower
hierarchical level, there is further congruence with
the uniquely expanded first cheliped in crangonoids
and alpheoids. My rearrangements of the traditional
families into superfamilies eliminate all the paraphyletic
family-level taxa, including the notably
unsatisfactory Hippolytidae. Finally, just to mention
one remarkable autapomorphy justifying one
of my new superfamilies, only palaemonids and
rhynchocinetids share a second distolateral tooth
on the basal segment of the antennule, in addition
to the usual stylocerite. Some researchers complain
that I presented few characters for each node, but
this is because my approach is qualitative and I selected
the best possible evidence from detailed studies
of the total morphological and species diversity
of the Caridea. To refute the phylogenetic system,
it is necessary that researchers argue for alternative
replacement characters where they believe I have
failed. Simply ignoring the system does not justify
the usual assumption that my arrangements are totally
wrong!
Submitted by Martin L. Christoffersen,
Federal University of Paraíba, Brazil
DECAPODA: REPTANTIA
I really do not understand why you do not use a
separate category for Reptantia. It is one of the
clearest, most universally accepted groups (taxonomically
or cladistically) among the decapods that
we have.
Submitted by Frederick R. Schram,
Zoölogisches Museum, Amsterdam
DECAPODA: ASTACIDEA
You really do get yourselves into deep water when
you try to offer editorial comments on cladistic
analyses. Here you hit another one. Where do you
get the idea of ‘‘extremely primitive Neoglyphea’’
from? Forest and de St. Laurent (1989, Nouvelle
contribution a la connaissance de Neoglyphea inopinata
a propos de la description de la femelle adulte,
Res. Camp. Musorstom 5, Memoirs Mus. Nat.
His. Nat., series A, 144:75–92) made [a] good argument
for allying glypheoids with astacids—not a
particularly primitive alliance. My own preliminary
examination of decapod phylogeny (submitted, Hydrobiologia)
not only fairly well confirms the
Scholtz and Richter scheme, but also squarely places
Neoglyphea within the Fractosternalia.
As I say, my own examination of the subject in
connection with an assignment to address decapod
phylogeny in connection with the beginning revision
of the decapod section of the Treatise on Invertebrate
Paleontology has, to my surprise, uncovered
the basic robustness of the Scholtz and Richter
analysis. I think you would do well to leave yourself
an opening here.
Of course, I see why you are keen to downplay
Scholtz and Richter because here you adapt a very
conservative combination of ‘‘clawed lobsters.’’ I
can accept this for now. However, I think it would
only be fair for you to point out that Scholtz and
Richter would segregate the ‘‘clawed (true) lobsters’’
as Homarida from the crayfish as Astacida.
My own on-going, recent work indicates that at
least the genus Neoglyphea is a fractosternalian in
some kind of proximity to the Astacida, and that
Enoplometopus may even be a separate clade from
the Nephropoidea. That this paraphyly should
emerge among ‘‘lobsters’’ is not too surprising,
since we discover again and again that supposedly
robust, traditional groups bearing a lot [of] plesiomorphies
emerge on closer examination as paraphyletic
taxa. Why should macrurous lobsters be
any different?
Submitted by Frederick R. Schram,
Zoölogisches Museum, Amsterdam
DECAPODA: ANOMURA
I fully agree with the different parts of my specialty
(Anomura). I agree with the changes included in
this new version. As you mention . . . we need more
studies (especially molecular) to improve our
110 Contributions in Science, Number 39 Appendix I: Comments and Opinions