Maximum-likelihood tree based on the COI haplotypes of Callinectes sapidus. The numbers in internal nodes are maximum-likelihood ultra-fast bootstrap support values produced with 1 000 replicates. The circle of haplotype network represents a single haplotype, and the size corresponds to the number of individuals within it. The number of mutations between the haplotypes is represented with the hatch marks and each hatch mark represents one nucleotide mutation.

 
 
  Part of: Kvach Y, Gabrielczak H, Lepekha A, Son MO, Khutornoi S (2025) The Chesapeake blue crab, Callinectes sapidus Rathbun, 1896: new finding, origin, and further spread in the Ukrainian part of the Black Sea. Aquatic Invasions 20(2): 199-214. https://doi.org/10.3391/ai.2025.20.2.154614