Figure 2 from: Bessesen BL, Galbreath GJ (2017) A new subspecies of sea snake, Hydrophis platurus xanthos, from Golfo Dulce, Costa Rica. ZooKeys 686: 109-123. https://doi.org/10.3897/zookeys.686.12682

Figure 2 - Hydrophis platurus xanthos sharply contrasts typical H. platurus in color, body size and behavior. A Scaled size comparison of yellow sea snake, TL 43 cm (left), and yellow-bellied sea snake, TL 69 cm (right; note the use of Vetrap as a calming mask and sickly condition of the specimen) B ambush posture of H. p. xanthos; floating at the sea surface at night in a sinusoidal shape, head below, mouth agape C although predominantly yellow, xanthic individuals often possess black spots along the dorsum.