Gourretia de Saint Laurent, 1973

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 : 119-120

Gourretia de Saint Laurent, 1973

Gourretia de Saint Laurent, 1973: 514 .— Le Loeuff and Intès, 1974: 26.— Poore and Griffin, 1979: 278.— Manning and Felder, 1991: 785.—Sakai, 2002: 468–469.— Ngoc-Ho, 2003: 498–499 .— Sakai, 2005b: 218–219 (partim).— Sakai, 2011: 510–511 (partim).

Pseudogourretia Sakai, 2005b: 230–231 .— Dworschak and Poore, 2018: 68–70 (type species, Pseudogourretia portsudanensis Sakai, 2005 , by original designation and monotypy).

Ivorygourretia Sakai, 2017a: 1126 , 1130 (type species, Gourretia barracuda Le Loeuff & Intès, 1974 , by original designation and monotypy) syn. nov.

Plantesgourretia Sakai, 2017a: 1126 , 1131 (type species, Gourretia nosybeensis Sakai, 2004 , by original designation and monotypy) syn. nov.

Ruiyuliugourretia Sakai, 2017a: 1126 , 1131–1133 (type species, Gourretia sinica Liu and Liu, 2010 , by original designation and monotypy) syn. nov.

Type species. Callianassa subterranea var. minor Gourret, 1887 , by original designation and monotypy (now Gourretia denticulata Lutze, 1937 [ Lewinsohn and Holthuis, 1986]).

Diagnosis. Rostrum sharply triangular, produced to near apex of ocular lobes, or obsolete, or obtusely triangular, flat, not reaching cornea (rarely). 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; carpus proximal and lower margins convex, swollen; propodus broad, with short fingers. 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, straight, dactylus longer, with sharp spines along opposing edges. Pereopod 3 propodus oval, little longer than wide, with short rounded proximal lobe on lower margin, lower margin straight, upper margin strongly convex. Male pleopod 1 article 2 with sharp distomesial apex, distal notch, sharp curved distolateral apex. Telson parallel-sided over anterior half, then tapering to evenly rounded apex.

Remarks. In species of Gourretia the minor cheliped propodus tapers evenly, the fingers are straight, the dactylus being slightly longer, and both fingers have sharp spines, almost hook-like in some, along their opposing edges. The fixed finger of the major cheliped is stout, as is the dactylus, and blade-like with a broad tooth. The fused appendices on the male pleopod 2 reach or overlap the end of the endopod. This contrasts with the minor chelipeds of species of Paragourretia whose fingers lack the sharp spines and curve distally, the fixed finger of the major cheliped evenly tapers and curves, and the appendices on the male pleopod 2 are midmesial, far from the apex of the endopod.

Sakai (2004) separated Paragourretia from Gourretia for two species (see discussion below). In Sakai (2011), the two genera were redefined and four additional species were reallocated to Paragourretia from Gourretia . The key character indicated then to separate the two genera was said to be the absence in Gourretia and presence in Paragourretia of a “lateral notch” on the uropodal exopod. A cardiac prominence is absent in the former but present in the latter according to their diagnoses. The presence or absence of a distal notch is sometimes difficult to judge—it is not a black and white character (see comments below under Paragourretia ). Our morphological analysis separates Paragourretia from Gourretia on the structure of the major and minor chelipeds, the shape of the propodus of pereopod 3 and the position of the appendices on the male pleopod 2, the notch being of lesser importance. None of these characters was included in the generic diagnoses by Sakai (2005b, 2011). The allocation of known species between the two genera is the same as that of Sakai (2011).

Pseudogourretia was synonymised with Gourretia by Dworschak and Poore (2018).

The male pleopod 1 of G. barracuda ( Le Loeuff and Intès, 1974) , said by Sakai (2017a) to be “hooked distally”, ends in a simple apex, a more subdued form of the bifid apex usual in this genus. The pleopod may be a subadult form. The appendix masculina of the male pleopod 2 is more adpressed to the endopod apex than typical but the basic structure is the same. Ivorygourretia , erected for only this species, is here synonymised with Gourretia .

Plantesgourretia Sakai, 2017 , erected for only G. nosybeensis , was said to have the male pleopod 2 “biramous; exopod shorter than endopod; endopod bilobed distally, and inner lobe bearing distally appendix masculina with setae, but no appendix interna”. The exopod is shorter in most species; the appendix masculina is more dominant than in other species but is otherwise similar; we give no importance to the absence of the appendix interna. G. nosybeensis is otherwise similar to all species of Gourretia ; Plantesgourretia is here synonymised.

Ruiyuliugourretia Sakai, 2017 , again erected for a single species, was said to have special male pleopods 1 and 2. The outline of pleopod 1 is typical of species of Gourretia and its supposed four articles are probable artefacts. Pleopod 2 is typical, except for the absence of an appendix interna, as in the previous species. Ruiyuliugourretia is here synonymised with Gourretia .

Gourretia loeuffintesi Sakai, 2005 , is a nomen nudum (no holotype designated).