Michelea Kensley and Heard, 1991

Poore And D, Gary C. B., 2015, Micheleidae (Crustacea: Decapoda: Axiidea): new family, generic and species synonymies, three new Australian species, and new records, Memoirs of Museum Victoria 73, pp. 95-105 : 97-98

Michelea Kensley and Heard, 1991

Michelea Kensley and Heard, 1991: 519 .— Poore, 1997: 373– 375.—Poore, 2008: 175.— Poore, 2004: 176–177.— Sakai, 2011: 311– 312.

Micheleopsis Sakai, 2010: 1462 (type species Micheleopsis orlik Sakai, 2010 , by original designation) Syn. nov.

Remarks. Poore (1997) diagnosed the genus and provided a key to the ten species known. Michelea dampieri Poore, 2008 , Michelea takeda Liu and Liu, 2012 , Michelea orlik ( Sakai, 2010) transferred from Micheleopsis , and the two new species described below can be added to his list. Members of the genus can usually be recognised by the presence of lamellae on the edges of the pleopodal rami but one of the new species described below lacks these lamellae. Otherwise, the extremely short rostrum, laterally compressed carapace, pereopodal setation, ovate uropodal rami, cylindrical eyestalks and the elongate first article of the antennule characterise the genus.

Sakai (2010) erected the new genus Micheleopsis that he said looks superficially similar to Michelea . For the important generic characters listed above the two do not differ. He noted that the carapace of the new genus (represented by a single individual of one species, M. orlik ) bears a dorsolateral carina running from each side of the rostrum to the posterior third of the gastric region – a similar carina has been illustrated for M. microphylla Poore, 1997 and is hinted at in other illustrations. The character would seem to rely on authors’ interpretations and illustrations. He noted that the maxilliped 3 exopod is rudimentary – it exceeds the ischium in all other species. This is one of several variable features of the genus, notably the number of gills and pleopodal lamellae, treated as being of specific value. Neither difference warrants separating a new genus from Michelea and it is here synonymised.

Sakai (2010) also stated that the specimen of M. orlik was a male with uniramous pleopods 1, with distal patches of hooks, and 2-articulate pleopod 2 endopods without an appendix masculina. His illustration seems of a somewhat distorted, damaged or teratological ramus – nothing like it appears elsewhere in axioids. Adult males of seven species of Michelea are known: M. abranchiata Poore, 1997 , M. dampieri , M. devanyi Poore, 1997 , M. imperieusae sp. nov., M. leura ( Poore and Griffin, 1979) , Michelea takeda and M. vandoverae ( Gore, 1987) – all have a male pleopod 1 typical of species in all micheleid genera, a stalked triangular blade with mesial hooks, and an appendix masculina on pleopod 2. Other species are known only from females or males in which pleopod 1 is absent or bud-like. The male holotype of M. lepta ( Sakai, 1987) lacks pleopod 1 and an appendix masculina on pleopod 2; M. microphylla Poore, 1997 has an obsolete simple pleopod 1 and lacks an appendix masculina. Representatives of all species being so few, growth-related change in micheleids has not been reported. Seven males of M. vandoverae (cl. 4.1–6.2 mm, USNM collections) all possess a typical pleopod 1 (C.C. Tudge, pers. comm. 9 Mar 2013). In this paper we report a male of M. leura without a male pleopod 1, of which a male, previously identified as its synonym M. paraleura Poore, 1997 , possesses a fully-formed pleopod.

The same variation occurs in Tethisea (see below). Dworschak (2008) documented similar changes in pleopod 1 in a somewhat related species, Neocallichirus karumba ( Poore and Griffin, 1979) . We conclude that full formation of the male pleopod 1 may occur over more than one instar (absence to bud-like to triangular). Genera based on what could be juvenile features, such as a less than fully formed male pleopod 1, can not be justified while uncertainty remains over allometric changes.

Micheleopsis is treated here as a junior synonym of Michelea . Neither the genus nor its only species was mentioned by Sakai (2011) in his otherwise comprehensive summary of Michelea and its included taxa.

About half of the 13 species of Michelea are Australian: M. dampieri Poore, 2008 , M. microphylla Poore, 1997 , M. hortus Poore, 1997 , M. leura ( Poore and Griffin, 1979) , M. novaecaledoniae Poore, 1997 newly recorded, and two newly erected here.