Genome sequences reveal global dispersal routes and suggest convergent genetic adaptations in seahorse evolution

CHUNYAN LI; OLAVE MELISA; HOU YALI; GENG QI; RALF SCHNEIDER; ZEIXA GAO; MEYER AXEL

NATURE COMMUNICATIONS

Springer Nature

Año: 2021 vol. 12 p. 1 - 11

2041-1723

Seahorses have a circum-global distribution in tropical to temperate coastal waters. Yet, seahorses show many adaptations for a sedentary, cryptic lifestyle: they require specific habitats, such as seagrass, kelp or coral reefs, lack pelvic and caudal fins, and give birth to directly developed offspring without pronounced pelagic larval stage, rendering long-range dispersal by conventional means inefficient. Here we investigate seahorses? worldwide dispersal and biogeographic patterns based on a de novo genome assembly of Hippocampus erectus as well as 358 re-sequenced genomes from 21 species. Seahorses evolved in the late Oligocene and subsequent circum-global colonization routes are identified and linked to changing dynamics in ocean currents and paleo-temporal seaway openings. Furthermore, the genetic basis of the recurring ?bony spines? adaptive phenotype is linked to independent substitutions in a key developmental gene. Analyses thus suggest that rafting via ocean currents compensates for poor dispersal and rapid adaptation facilitates colonizing new habitats.