Gurneya Brtek 1996

Rogers, D. Christopher, 2006, A genus level revision of the Thamnocephalidae (Crustacea: Branchiopoda: Anostraca), Zootaxa 1260, pp. 1-25 : 14-15

Genus Gurneya Brtek 1996

Dendrocephalus Gurney 1931 . Branchinella Belk & Brtek 1995 . Gurneya Brtek 1996 .

Diagnosis (Based upon the literature)( Figure 1 F). Fully everted penes apparently extending to third abdominal segment. Basal portion chitinized, with lateral sub­conical projection. Everted portion with a single, large, ventroproximal, chitinized, anteriorly directed, straight spine. Distal portion of everted penes, expanded, with one ventral, one lateral, and one medial longitudinal row of spines, and a single apical transverse row of spines that joins the ventral spine row. Brood pouch sub­globular basally, distal portion free, sub­cylindrical, and extending to abdominal segment three or four to nine. Male with a frontal appendage. Male second antennae slightly coalesced medially. “Antenna­like” appendages absent. Female second antennae broadly lamellar. One species, G. m i r u s (Gurney 1931), from Paraguay.

Comments. This is the only genus where material was not available for this study. Belk & Brtek (1995) recognized that G. m i r u s was different from Dendrocephalus , and moved it into the ‘catch­all’ genus Branchinella without providing any definitive analysis. Brtek (1996) later created the genus Gurneya for this species, despite strong reservations from Belk (pers. comm.). Brtek defined this new genus primarily on the morphology of the frontal appendage. Although the penal morphology appears distinct (based upon the sketches in the original description and Brtek 1996), this genus needs a close reevaluation. This genus shares many similarities with Dendrocephalus , particularly in the form of the male frontal appendage the second antennae, and the form of the brood pouch. Dendrocephalus and Gurneya share similar egg morphology (compare the photographs in Cesar 1989 of Gurneya with Dendrocephalus ). Both genera have similar male genitalia, sharing the basic overall form of the everted penes. However, the eversible portion of the penes in Dendrocephalus have a ventral, longitudinal row of large, posteriorly directed spines, with scattered spines in short rows on the medial and dorsal distal third. The everted genitalia of Gurneya appear to be far more heavily armed with well defined dorsal, ventral, lateral and medial longitudinal rows of recurved spines.

Figures

FIGURE 1. Representative left penes of thamnocephalid genera and subgenera: A) Thamnocephalus platyurus, ventral view; B) Carinophallus ornata upper image (with penes retracted) left ventrolateral view of genital segments; lower image ventral view of everted pene; C) Dendrocephalus c ervicornis, ventral view; D) Dendrocephalus (Dendrocephalinus) acacioidea, ventral view; E) Phallocryptus sublettei, ventral view; F) Gurneya mirus, ventral view; G) Branchinella wellardi, ventral view; H) Branchinella budjiti, ventral view; I) Branchinella (Branchinellites) ondonoguae.