Gouws, Gavin; Kruger, Jerraleigh L; Smale, Malcolm; Henriques, Romina; Potts, Warren M: Otolith measurements for the comparison of two species of sciaenid fishes, Atractoscion aequidens and Atractoscion macrolepis [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.974715 (dataset in review)

Morphometric data were collected and meristic counts taken from up to 33 museum-vouchered specimens of Atractoscion aequidens, sampled from South African coastal waters, and 52 specimens of Atractoscion macrolepis from Angolan coastal waters. The latter included museum-vouchered specimens and specimens collected in the field (but not retained in collections) during May and June 2009. Musuem specimens were from the South African National Fish Collection housed at the National Research Foundation - South African Institute for Aquatic Biodiversity. Additionally, specimen length and 8 measurements and one count were taken from otoliths removed from 17 specimens of Atractoscion aequidens and 27 specimens of Atractoscion macrolepis, from South African and Angolan waters respectively. Otoliths from Atractoscion aequidens were sourced from the South African National Otolith Reference Collection, housed at Bayworld - Port Elizabeth Museum. Otoliths from Atractoscion macrolepis were removed from some of the specimens included in the morphometric and meristic dataset, sampled from Angola during 2009. Data were collected to investigate morphometric and meristic differences between the two species to confirm or refute the earlier description of A. macrolepis as a distinct species, and to examine characters that would allow the distinction of the two species, if valid. The earlier description of A. macrolepis was based on a limited number of specimens, and the proposed diagnostic character is unable to discriminate the species when considering a wider sample. Otoliths were measured using digital calibers, under a stereoscopic dissection microscope under direct light, with the counts of the processes being made with translucent backlight. Otolith measurements included the otolith height (OH), otolith length (OL), the ostium to cauda distance (OCD), the distance from the top of the otolith to the bottom of the cauda (TOBC), the width of the cauda (WC), the width of otolith at the cauda (OW), and the number of processes on the back of the otolith (Processes).