Stygobromus bakeri, a new species of groundwater amphipod (Amphipoda, Crangonyctidae) associated with the Trinity and Edwards aquifers of central Texas, USA

Abstract

A new stygobitic groundwater amphipod species, Stygobromus bakerisp. nov., is described from 4 central Texas limestone karst springs; John Knox Spring (Comal County), Jacob’s Well (Hays County), Mormon Spring (Travis County) and Salado Springs (Bell County). This species belongs to the predominately western Nearctic hubbsi species group of Stygobromus and differs from other species in the group by gnathopod 1 with row of 4 to 5 setae posterior to the defining angle, pereopods 6 and 7 with broadly expanded bases and distinct distoposterior lobes, gnathopods 1 and 2 with 2 rows of 3 singly inserted setae on the inner palm, and uropod 3 with single, slightly distal peduncular seta. Habitat, sympatric groundwater species, and conservation issues are discussed.

A new genus, Tuberocandona gen. nov. (Crustacea, Ostracoda, Candonidae) and past to present ostracod species diversity in Texas (USA)

“…Hence, considering the areas and habitats not sampled and/or not studied yet, the State of Texas will probably contain a much higher species diversity than what we have already discovered. Indeed, contemporary studies in different taxonomic groups (Gibert et al 1990;Bowles and Arsuffi 1993;Hall et al 2004;Segers 2008;Hutchins et al 2020;Gibson et al 2021) also support this view that the area has high species diversity including epigean, subterranean and groundwater habitats. Studies on the fossil ostracods revealed similar results and even much higher species diversity.…”

“…Contemporary studies on nonmarine ostracods (Külköylüoğlu et al 2011(Külköylüoğlu et al , 2017a(Külköylüoğlu et al , b, c, d, e, 2019(Külköylüoğlu et al , 2021(Külköylüoğlu et al , 2022Külköylüoğlu and Gibson 2018;Külköylüoğlu 2020;Külköylüoğlu and Tuncer, in press), as well as other taxonomic groups (Reddell and Mitchell 1969;Hall et al 2004;Segers 2008;Hutchins et al 2020;Gibson et al 2021), have clearly shown that the State of Texas contains highly unique species diversity and richness. However, knowledge about fossil fauna is not complete and there are gaps in the evolutionary record that need filling.…”

A new species of Stygobromus Cope, 1872 (Amphipoda, Crangonyctidae) from a hypotelminorheic seepage spring in Washington, D.C., USA

“…The discovery of a new species of Stygobromus amphipod from the Piedmont and Atlantic Coastal Plain is not surprising given high species richness of the genus not only in the region but also throughout North America, and the description of several species in recent years throughout the United States (Holsinger et al 2011;Holsinger and Ansell 2014;Holsinger and Sawicki 2016;Cannizzaro et al 2019;Gibson et al 2021). Moreover, uncovering cryptic diversity is an increasingly common finding of population genetic and phylogenetic studies in groundwater fauna (Lefébure et al 2006;Murphy et al 2009;Zakšek et al 2009;Niemiller et al 2012Niemiller et al , 2013Devitt et al 2019), including crangonyctid amphipods (Etheridge et al 2013;Niemiller et al 2018;Cannizzaro et al 2020).…”

Uralocrangonyx gen.n. (Amphipoda: Crangonyctidae) from the Southern Ural, Russia

“…Currently, more than 50 species of Eucrangonyx and 130 species of Stygobromus have been discovered in the Nearctic [Cannizzaro, Savicki, 2019;Gibson et al, 2021;Cannizzaro et al, 2021]. At the same time, taking into account the inequality of known crangonyctid across the Palearctic and even Russia, the endemicity of many species (for example, Lyurella spp.…”