The Shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae)
Author
Błażewicz-Paszkowycz, M.
Author
Bamber, R. N.
text
Memoirs of Museum Victoria
2012
69
1
235
journal article
1447-2554
F060EED2-88C1-4A9A-92A7-6C06905F307B
Family
Tanaopsidae
fam. nov.
Diagnosis
. Generally leptognathioid (
sensu
lato
) facies, pleon laterally convex and wider than pereon, antennule in female of four longer articles with or without minute distal article, in male with multisegmented flagellum; mandible pars incisiva distally rounded with adjacent serrated incisive margin, molar process either slender and pointed or absent; maxillule endite reflexed through about 90° and with five or six distal spines, one significantly more robust than the others; maxilliped endite flared. Cheliped with triangular, dorsally-inserted sclerite, fixed finger with two ventral setae, bifid terminal spine and bifid or trifid distal denticle on incisive margin. Pereopods 1 to 3 with setae, unguis longer than slender dactylus, both together about as long as or longer than propodus, dactylus with proximal seta; pereopods 4 to 6 with spines on merus, carpus (three in number) and propodus. Pleopods with plumose seta along entire outer margin of exopod, but restricted to distal half of outer margin of endopod; uropods biramous, rami with one or two segments.
Type
genus
:
Tanaopsis
Sars, 1896
Remarks
. The present suprageneric classification of the
Paratanaoidea
is in a state of flux, owing to recent attempts at phylogenetic resolution involving cladistics, based on meristics and morphometrics (
Larsen & Wilson, 2002
;
Błażewicz-Paszkowycz & Poore, 2008
;
Bird & Larsen, 2009
). The only of these studies to consider the genus
Tanaopsis
were
Larsen & Wilson (2002)
and
Błażewicz-Paszkowycz & Poore (2008)
, but they were unable to resolve it to a family as defined by their generated clades.
The diagnostic features listed above taken together distinguish members of the genus
Tanaopsis
from all other paratanaoid genera of the leptognathioid
sensu
lato
facies; that said, they constitute a diagnosis of the genus itself. Equally, exclusion of the unique features of the cheliped fixed finger does not allow inclusion of any other genera. Further detailed cladistic analyses may associate other genera, which would then require qualifying the familial diagnosis above, removing characters not consistent across all associated genera into the diagnosis of the genus
Tanaopsis
.
Bird (2011)
suggests possible affinities with
Cristatotanais
Kudinova-Pasternak, 1990
(including
Spinitanaopsis
Larsen, 2005
).
It is further the case that
Tanaopsis
itself may not be monophyletic. There appear to be two groups of species, one with a pointed mandibular molar process and two-segmented uropod rami (
T. antarcticus
Lang, 1967
;
T. cadieni
Sieg & Dojiri, 1991
;
T. curtus
Kudinova-Pasternak 1984
;
T. gallardoi
(
Shiino, 1970
)
;
T. profunda
Lang, 1967
;
T. canaipa
Bamber, 2008
and one of the two species described below), the other without a molar process and with one-segmented uropod rami (
T. chotkarakde
Bird & Bamber, 2000
;
T. kerguelenensis
Shiino, 1979
[mandible unknown]; and one of the two species described below); the latter group also tend to have a more slender antennule. That said,
T. laticaudata
Sars, 1882
is described as being without a mandibular molar (Sars, 1896), but has two-segmented uropod rami. It is at present not possible to distinguish such groups as separate genera, as the
type
species of
Tanaopsis
sensu
stricto
,
T. graciloides
(Lilljeborg, 1864)
needs proper redescription based on material from the northwest Atlantic (see Bamber
et al
., 2009).