RESUMEN
We describe the complete mitochondrial genomes of the flapper skate Dipturus intermedius (Parnell 1837) and the longnose skate Dipturus oxyrinchus (Linnaeus 1758), which have been obtained by Sanger sequencing. We report the length of the sequences to be 16,906 and 16,911 bp, respectively. The length and structure of gene regions, containing 13 protein-coding regions, 22 tRNA genes, two rRNA genes, and two non-coding areas, resemble those of related skate species. Despite D. intermedius being considered a cryptic species with D. batis, the full mitogenomes confirm that D. intermedius and D. oxyrinchus are more genetically similar. In comparison to other Dipturus species, D. intermedius is missing a whole codon in its cytochrome oxidase subunit 2 gene. These mitogenomes will be a useful resource furthering investigation of the population genetic differences and evolutionary history of skate species.
RESUMEN
An egg of the critically endangered flapper skate Dipturus intermedius was successfully incubated to hatching in captivity in what is believed to be a first for the species. Water conditions (temperature, salinity, flow rate) were recorded, with mean water temperatures ranging from a monthly mean of 8.3 ± 1.2 to 13.2 ± 0.3°C and salinity from a monthly mean of 30.5 ± 1.2 to 36.6 ± 2.3 ppt. Hatching occurred after 534 days, suggesting that flapper skate eggs take c. 5700 growing degree-days to incubate to hatching. The egg's prolonged embryonic development raises concerns about flapper skate eggs' vulnerability to anthropogenic disturbance.