Paragourretia Sakai, 2004

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 121

Paragourretia Sakai, 2004

Paragourretia Sakai, 2004: 568–569 .— Sakai, 2005b: 225.— Sakai, 2011: 516.

Heterogourretia Sakai, 2017a: 1126 , 1129–1130 (type species, Gourretia aungtonyae Sakai, 2002 , by original designation and monotypy) syn. nov.

Tuerkaygourretia Sakai, 2017a: 1126 , 1133 (type species, Tuerkaygourretia galathea Sakai, 2017 , by original designation and monotypy) syn. nov.

Type species. Gourretia phuketensis Sakai, 2002 , by original designation and monotypy.

Diagnosis. Cardiac prominence absent (rarely), or present. Rostrum sharply triangular, produced to near apex of ocular lobes, or obsolete, or obtusely triangular, flat, not reaching cornea. Pleomere 6 without or with ( P. biffari only) lateral projections. Maxilliped 3 with exopod. Male major cheliped merus with straight or weakly convex blade on lower margin bearing a short proximal curved spine and 1 or more distal spines; propodus rectangular, fingers tapering, fine, fixed finger smooth. Minor cheliped merus lower margin with erect proximal spine (as in major cheliped); propodus tapering, about 3 times as long as wide; fingers evenly tapering, curved distally, of equal lengths, smooth or with obscure denticles along opposing edges. Pereopod 3 propodus linear, longer than wide, without proximal lobe on lower margin, lower margin straight, upper margin moderately convex. Male pleopod 1 article 2 with sharp distomesial apex, distal notch, and sharp curved distolateral apex. Telson parallel-sided over anterior half, then tapering to evenly rounded apex.

Remarks. Paragourretia differs from Gourretia in having fingers lacking the sharp spines seen in Gourretia and curving distally, the fixed finger of the major cheliped evenly tapering and curving, and the appendices on the male pleopod 2 being midmesial, far from the apex of the endopod rather than distal. None of these characters was mentioned by Sakai (2011) although his allocation of species between the two genera is identical to ours. None of the specific diagnoses of members of this genus and of Gourretia in Sakai (2011) includes other than an idiosyncratic assemblage of family and generic features and none that tell one species from another. Paragourretia biffari shares with Dawsonius latispina lateral projections on pleomere 6.

Sakai (2004) likened Paragourretia to Dawsonius , not Gourretia , because of a thick carapace and a cardiac prominence. Re-examination of the type species failed to convince GCBP that the carapace differed from other species of Gourretia in this regard. A transverse cardiac sulcus was difficult to decipher, and a transverse row of setae on the anterior branchial region said to also characterise the genus is found in all ctenochelid species examined. Sakai (2011) changed the emphasis of his re-diagnosis, this time relying on the presence of a notch on the uropodal exopod and on simple versus subchelate pereopod 4 (it is simple in both genera). This notch might be a precursor to a “dorsal plate”, or as in some species, an elevated anterior margin over the posterior part of the exopod, the two separated by transverse furrow. While the notch is clear and unmissable in some species, in others it is more ambiguous. The notch is a vague concavity in the type species P. phuketensis and absent in P. lahouensis (which Sakai curiously included in his key to species, identifiable as “without lateral notch”). The notch is absent in all species of Gourretia . Paragourretia was synonymised with Gourretia by Sakai (2017b) because they have similar male pleopods 1 and 2. In fact, in species of Paragourretia the appendices on the midmesial margin do not reach the end of the endopod whereas in Gourretia s.s. they do, as far as is known.

Gourretia aungtonyae was provisionally included in Paragourretia by Sakai (2005b) and made type species of a new genus Heterogourretia ( Sakai, 2017a) because of the absence of male pleopod 1 and a distal “segmented” appendix interna on pleopod 2. The holotype male has carapace length of 2.9 mm and an ovigerous female 3.6 mm. The small size of the male suggests it is immature and lacks male pleopod 1 for this reason. The figured appendix interna is atypical of axiideans and possibly an artefact. In all other features, the species is typical of Paragourretia . For these reasons, Heterogourretia is synonymised with Paragourretia .

The type species of Tuerkaygourretia , T. galathea Sakai, 2017 , was based on a holotype female from Tranquebar, SE India ( Galathea stn 290), two paratypes from the same station, two females from the Bay of Bengal, India ( Galathea stn 304), and one male from Singapore ( Galathea stn 357). The figures of the holotype ( Sakai, 2017a: figs 4A, B, C, E, F, 5A–C, E, G) are of a species of Paragourretia showing the minor cheliped without teeth, uropodal exopod with a notch and pereopod 3 with a narrow propodus having the lower margin straight. Other figures are problematic, somewhat undermining Sakai’s (2011) argument for new genera based on differences in male pleopods. Fig. 5I of pleopod 2 (said to be from the type locality) and fig. 5D of a broad pereopod 3 (from the Thai-Danish Expedition stn 1160 but not otherwise listed) are of a species of Gourretia . Other figures from the Thai-Danish Expedition stn 1160 are fig. 5H of pleopod 2 of a species of Gourretia (appendices terminal) and figs 5J, K of a species of Paragourretia (appendices mesial). Sakai (2017a) attributed differences between these two forms to size. It is apparent that more than one species, from both Gourretia and Paragourretia , have been confounded in this description. Sakai (2017a) did not explain how these pleopodal forms differed from those of other genera. To add further confusion, the species’ distribution is given as “Off Tranquebar, India (type locality); W. of Subitana, Port Moresby, Papua New Guinea; West Malay Peninsula; Singapore Island ” but material is listed for only the first and last of these four; the Thai-Danish Expedition stn 1160 would appear to be on the West Malay Peninsula. Tuerkaygourretia is synonymised with Paragourretia on the basis of probable illustrations of the holotype and paratype.

Figures

Figure 5. Diagnostic characters of Anacalliacidae, Anacalliax: a, dorsal anterior carapace, eyestalks, antennules, antennae; b, lateral carapace; c, maxilliped 3; d, male pleopod 1; e, female pleopod 2; f, telson, uropod.