Bioacoustics of Aglaothorax bufonoides

Stridulatory file. (n=4) length 3.00– 3.90 mm , 87–110 teeth, tooth density 29.3±3.2 (25.2–32.0) teeth/mm. Song. (n=12) Standard song for small Aglaothorax with pulse trains that occur slow enough for a human listener to count. Pulse trains of 60±10 ms produced at a rate of 5.31± 1.19 s- 1. Mean peak frequency is 13.90±1.10 kHz. Echemes contain a variable number of pulse trains (mean 22±11, range 4–39 pulse trains), the echeme rate is 4–7 min-1 . Karyotype. (n=13) 2n ♂ =24 ( 22t +XtYt), paratype JCT19-6 , paratopotype S89-21, T89-10 . Type locality T89- 10 (S89-21) 2n ♂ =24, metaphase I clearly showing associated XY sex chromosomes and 11 pairs of autosomes. Recognition. Morphology, karyotype. The male supra-anal plate is rounded and concave and the paraproct processes are twice as long as wide, with an apical or slightly subapical mesal tooth. A. nesiazo to the north in the Peninsular Ranges of California has a square supra-anal plate and long, slender paraproct processes, more than two times longer than wide. From Baja California congeners, A. sphenosternum has the prosternal spines wedgelike whereas A. bufonoides has typical long, thin spines. The male titillator arms are short and curved laterally, unlike the nearly straight arms of A. nesiazo distributed to the north and A. kelainops to the south. Females of A. bufonoides have the subgenital plate lateral processes as long as wide while those processes are longer than wide in A. kelainops . The karyotype of A. bufonoides is typical for small Aglaothorax at 2n ♂ =24; A. kelainops and A. sphenosternum have atypical karyotypes that are discussed below.

Etymology. G. bufo toad + oid like, form. Descriptive of the toad-like gestalt of the genus. Notes. This is the most widespread Aglaothorax in Baja California . The species is alone on the Baja California peninsula in possessing the widespread small Aglaothorax karyotype of 2n ♂ =24. Populations with the three different karyotypes have not been found in any combination of sympatry, but ranges may be adjacent ( Fig. 15 ). Songs are not divergent between the three Baja California taxa nor from coastal San Diego A. nesiazo . Phylogenetically, this species is related to A. nesiazo to the north, and two different haplotypes are in turn sister to each of two Aglaothorax with divergent karyotypes ( Figs. 3–4 ): A. kelainops (2n ♂ =20) and A. sphenosternum (2n ♂ =22).