Maera, Leach, 1814

Lowry, JK & Springthorpe, RT, 2005, New and Little-known Melitid Amphipods from Australian Waters (Crustacea: Amphipoda: Melitidae), Records of the Australian Museum 57, pp. 237-302 : 239

The Maera complex

Krapp-Schickel & Ruffo (2000) recently established the genus Quadrimaera and transferred four of the nine Australian species, previously considered to be Maera , to this genus (Table 1). Krapp-Schickel (2003) recently reestablished the genus Linguimaera Pirlot, 1936 and described seven new Australian species in the genus. But five remaining Australian species are still unassigned.

In the original description of Maera mastersii Haswell, 1879a , the illustrations of uropod 3 and the telson differ significantly from those presented by Sheard (1936) and J.L. Barnard (1972a). We examined syntype material and new material, both from Port Jackson, that agree with the description and illustrations of Haswell (1879a). Based on this material we redescribe the species and place it in the new genus Austromaera . Within Australia, the material considered by Sheard (1936) as Maera mastersii has been described as Linguimaera tias Krapp-Schickel, 2003 and that of J.L. Barnard (1972a) has been described as Linguimaera leo Krapp-Schickel, 2003 . Krapp-Schickel (2003) has also reestablished the Torres Strait species, Maera thomsoni (Miers, 1884) (synonymized with M. mastersii by Haswell, 1885), and transferred it to Linguimaera .

Two main characters define Linguimaera Pirlot, 1936 (Krapp-Schickel, 2003). The first is the second gnathopods of the male that are always asymmetrical, so that one is similar to the female second gnathopod and the other is enlarged and morphologically dissimilar, as is typical of mate-guarding amphipods. The second character is a serrate posterior margin on epimeron 3 (weakly serrate in M. hamigera ). Among the Australian species in our study, Maera boecki Haswell, 1879 , M. hamigera Haswell, 1879 and M. octodens Sivaprakasam, 1968 , all have these characteristics. They are here transferred to the genus Linguimaera . In addition, a new species, Linguimaera schickelae n.sp., is described from the Sydney area.

The original description of Maera boecki Haswell, 1879b , was inadequate and the type material is apparently lost (Springthorpe & Lowry, 1994). As a result the species has been unidentifiable. Della Valle (1893) referred to it as? Maera boeckii . Stebbing (1899) transferred it to Elasmopus in his world monograph (Stebbing, 1906). K.H. Barnard (1916) appears to have erroneously reported E. boecki from South Africa. Since Sheard (1937) placed it in his catalogue of Australian Gammaridea, there have been no further records or new material. While studying material for the Australian Amphipod Project, we discovered material from Port Jackson that we are referring to this species. The species has all the characteristics of a Linguimaera , except for an emarginate telson, which appears to be independently derived.

The name Maera hamigera Haswell, 1879b (type locality Port Jackson), has not been used for an Australian species since Stebbing (1910a), but it has been used for species living in the Red Sea (Walker, 1909; Lyons & Myers, 1993), southern Africa (K.H. Barnard, 1916), Micronesia (J.L. Barnard, 1965), the Mediterranean Sea (Karaman & Ruffo, 1971), Madagascar (Ledoyer, 1982) and Western Samoa (Myers, 1997). A microscope slide from the syntype series shows the unusual gnathopod 2 of this species. Using this evidence we discovered many specimens of this species in collections from Twofold Bay on the south coast of New South Wales. We redescribe the species here, based on the syntypes and the newly discovered material. These results indicate that L. hamigera is currently confined to southeastern Australia. Material from other areas that also appears to be in the genus Linguimaera , and has been attributed to this species, needs to be re-examined. Krapp-Schickel (2003) recently renamed material, identified as M. hamigera , from the Mediterranean, the Red Sea, Madagascar and Western Samoa as L. caesaris , but left the material from southern Africa and Micronesia unresolved.

Stebbing (1910a) identified material from the Thetis Expedition as Maera inaequipes (Costa, 1851). Even as he did, he stated that “the specimens … do not justify the specific name”. We establish the new genus and species Miramaera thetis based on material in the Australian Museum collections and transfer the New Zealand species, Maera tepuni J.L. Barnard, 1972b , to Miramaera .

Based on the key in Krapp-Schickel (2000) and unpublished phylogenetic analyses (JKL) we tentatively place Maera griffini Berents, 1983 , in the genus Maeropsis Chevreux, 1919 . Krapp-Schickel & Ruffo (2001) deduced that Maera tenella of Tattersall, 1922 (Wooded Island, Abrolhos Islands) is actually a species of Maeracoota Myers, 1997 . Unfortunately material of this species is not available for study.