Phallocryptus wrighti (Smirnov, 1948)

Rogers, D. Christopher, 2003, Revision of the thamnocephalid Genus Phallocryptus (Crustacea; Branchiopoda; Anostraca), Zootaxa 257, pp. 1-14 : 3-5

Phallocryptus wrighti (Smirnov, 1948)

( Figure 1 a, 2a – e)

Branchinella wrighti Smirnov, 1948

Phallocryptus salinicola Biraben, 1951

Phallocryptus wrighti (Smirnov, 1948) Belk & Brtek, 1995 ; Brtek, 1995 Diagnosis: Male: Cephalic appendages absent. First antennae twice as long as eye plus stalk. Second antennal proximal segment subequal in length to first antennae, subcylindrical, medial surface with small spines. Second antennal distal segment two to three times the length of the proximal segment, arcuate, curving posteriorly, and tapering to an acute apex. Praeepipodite may bear one or more small notches, but is not subdivided. Ventral surface of first genital segment with a single large, posteriorly directed tubercle, as long as the basal portion of the penes, projecting dorsally over the penes. Basal portion of penes with a medial, posteriorly directed, hooked projection, truncated apically. First abdominal segment (first post­genital segment) with a large, medial, ventral, ventrally directed, subacute, stout, spine–like projection on the distal margin of the segment. Each abdominal segment with a small, distal, ventro­lateral spine, directed ventro­laterally.

Female. First antennae nearly twice as long as second antennae, or eye plus stalk. Second antennae joined basal­medially, slightly produced medially. Brood pouch sub­globular, tapering posteriorly to apex. Apex produced half way along first abdominal segment. Gonopore produced ventro­distally, with dorsal “lip” longer than ventral lip. Each abdominal segment with a small ventro­lateral spine, directed ventro­laterally.

Resting cyst: Sub­spherical with shallow sub­oval depressions, separated by thin ridges. Micrograph of cyst in César (1989).

Type Locality. Las Encadenadas, near Saavedra, Buenos Aires Provence, Argentina

Type. The types are apparently lost. Cotypes (accession numbers 13490 and 13491) were deposited by Biraben (1951) at the Museo de Ciencias Naturales de La Plata in La Plata City, Buenos Aires Province.

Distribution. North and central Argentina in the Buenos Aires, Catamarca, Cordoba, La Pampa, La Rioja, and San Juan Provinces.

Habitat. Saline lakes and pools.

Activity Period. March, December.

Comments. P. wrighti co­occurrs with Thamnocephalus (Simplicephalus) salinarum Cohen, 2002 ( Cohen et al., 1999; Cohen, 2002), and occurs in pools adjacent to habitats occupied by Dendrocephalus cervicornis (Weltner, 1890) .

Conservation status. This species is sufficiently widespread, with no known immediate threats and is designated here as a species of “Least concern” (IUCN, 2000).

Material examined: ARGENTINA: La Rioja/San Juan Province Border: Ditch on north side of Highway 141, at the 85 km marker, west of Chapes, 1 female, 8 March 1987, K. Reading. Córdoba Province: Salinas Grandes, 2 males, 2 females, 19 December 1998, S. Vernet.

Figures

FIGURE 1. Phallocryptus, male genitalia: A) P. w r i g h t i; B) P. sublettei; C) P. s p i n o s a.