Dataset: RNA:DNA measurements for field-collected animals from the Gulf of Mexico Estuary near Port Aransas and Mud Island, Texas from 2020 to 2021

Location: Gulf of Mexico Estuary near Port Aransas, Texas. FAML: pier at in Corpus Christi Channel, Port Aransas, TX, United States, Fisheries and Mariculture Laboratory of the University of Texas Marine Science Institute (lat. 27.8396111, lon. -97.0827222); MI: Mud Island in Aransas Bay, TX, United States (lat. 27.9362222, lon. -97.0217777)).

RNA:DNA ratios, which are indicators of animal condition, were measured for samples of egg consumers collected from the field as well as those used in laboratory experiments. Samples of small fishes were collected with cast nets or seines. Fishes were euthanized with lethal dose of MS-222. The euthanized fish were placed on ice and muscle plugs were collected. All samples were lyophilized and stored at -80°C until being processed for RNA:DNA analysis. The time between collection and analysis ranged from 15 to 444 days. Results of the analysis were reported as the ratio of RNA content to DNA content.

Measurements of RNA:DNA were made on individuals. DNA and RNA were measured using the ethidium bromide (EB) fluorometric technique (Westerman and Holt 1988) based on aliquots (10 µL) of homogenates. Calculations were based upon comparisons with DNA-EB and RNA-EB calibration curves from calf thymus DNA and yeast RNA (Type 111) standards. RNA:DNA ratios were normalized using a standardization factor based on the common RNA:DNA slope ratio procedure described by Caldarone et al. (2006). Results of the analysis were reported as the ratio of RNA content to DNA content. Measurements of RNA:DNA were unsuccessfully attempted for invertebrates.