Branchinella affinis, Linder, 1941

Timms, Brian V, 2012, Further studies on the fairy shrimp genus Branchinella (Crustacea: Anostraca: Thamnocephalidae) in Australia, with descriptions of five new species, Zootaxa 3595, pp. 35-60 : 36-38

B. affinis Linder, 1941

( Fig. 1 A, B)

B. affinis Linder, 1941 , pp 257–61, fig. 36; Geddes, 1981, p.271–272, Fig. 10 ; Timms, 2002, p73, Fig.2 . B. affinis var. wonganensis Linder, 1941 , p.261, fig.39d.

B. clandestina Timms, 2005 , p. 441–444, Figs.1 , 2 A. New Combination

Material. New South Wales, stock dam 19.5 km SE of Wilcannia, 31o 43’ 05”S, 143o 27’ 50”E, 20 January 2007, BVT, AM P88357; Queensland, 58 km NW of Hungerford on Hungerford-Thargomindah Rd, claypan, 28o 50’ 23”S, 143o 53’ 46”E, 26 February 2011, BVT, AM P88358; Queensland, 84 km S of Thargomindah on Hungerford-Thargomindah Rd, floodout of a stock dam, 28o 39’ 47”S, 143o 48’ 41”E, 26 February, 2011, BVT, AM P 88364; Queensland, 36 km N of Thagomindah on Thargomindah-Quilpie Rd, ‘Yapunyah pool,’ 27o 49’ 10”S, 144o 09’ 26”E, 28 February, 2011, BVT, AM P88359; Northern Territory, Alice Springs, Ilparpa claypan, 23o 45’ 14”S, 133o 47’ 52”E, 22 Januray 2010, Jochem van der Reijden, AM P88363; Northern Territory, Horseshoe Bend Station on the Finke River, a claypan, ca 25o 13’S, 134o 15’E, 26 April 2004, Magdalena Zofkova. AM P88360; South Australia, 40 km N of Marla on Stuart Highway, a claypan, 26o 59’ 50”S, 133o24’58”E, 10 March 2011, BVT, AM P88361; South Australia, ca 23 km E of Oodnadatta Track at Algebuckina Crossing of the Neales, Gidgee Ck, 27o 57’ 10”S, 136o 03’ 30”E, 2 April 2001, Peter Hudson, SAM C7035; South Australia, 18 km N of William Creek on Oodnadatta Track, a claypan, 28o 51’30, 136 o 09’ 49”E, 12 March 2011, BVT, AM P88362.

Remarks. Branchinella affinis occurs across Australia ( Timms, 2004) and is one of the more variable Branchinella species ( Geddes, 1981). This variability is partly documented by Geddes (1981) to which must now be added the slightly different form of B. clandestina . In a molecular analysis of the 16SmtDNA region, Pinceel et al. (2012) found the genetic difference between B. clandestina and B. affinis to be only 1.8%, far less than a difference>4% that Adamowicz & Purvis (2005) and Adamowicz et al. (2009) claim to differentiate species for rDNA coding genes. The diagnostic features of B. clandestina , namely the unusually narrow frontal appendage, its branching at about 5/6ths the length, limited sensory papillae on the frontal appendage branches, and the curving in three planes of the basal segment of the second antennae ( Timms, 2005) should now be considered as further variations in morphology of B. affinis . The egg is not different ( Fig. 1 B), but then eggs of B. affinis are not distinctive (Timms and Lindsay, 2011). All of these variations have been seen in recent years in various degrees in specimens from many sites across Australia, including those listed in the materials from areas not previously collected. For instance, the two specimens from near Wilcannia, New South Wales, have claspers shaped like those in the B. clandestina , but otherwise would be considered B. affinis sensu stricto. So, B. clandestina is regarded as a junior synonym of B. affinis . Further work, especially using molecular techniques, is needed to understand variation within this taxon. The description of B. erosa sp. nov. below is the first attempt at this.

Figures

FIGURE 1. Resting eggs of selected species of Branchinella. A, B. affinis; B, B. clandestina n. syn.; C, B. anatinorhyncha; D, B. compacta; E, B. erosa sp. nov.; D, B. compacta; F, B. hearnii sp. nov.; G, B. herrodi sp. nov.; H, B. simplex; J, B. wellardi. Scale bars 50 µm. Images modified from Timms and Lindsay, 2011.

FIGURE 2. Branchinella anatinorhyncha sp. nov. A, male second antenna, dorsal view; B, frontal appendage; C male head and anterior thorax, lateral view; D, male gonopods; E, male penis; F, female head anterior view; G female genital segments and associated abdominal segments. Scale bars 1 mm.

FIGURE 10. Branchinella minmina sp. nov. A, male second antenna with frontal appendage, dorsal view; B, male second antenna and anterior thorax, lateral view; C, male gonopod and penis; D, female head anterior view; E, female genital segments and brood pouch. Scale bars 1 mm.