A maximum likelihood tree of the 16S rRNA haplotypes found in cave and surface specimens. B minimum spanning haplotype network. Most similar sequences obtained in GenBank through BLAST analyses plus a sequence of C. cognatus from Willsey Brook, NY, are also included in the trees. Two distinct lineages were identified; one that includes C. bairdii specimens and one that includes C. cognatus. Cave haplotypes within the C. bairdii clade are identified by numerals (1–2) and Cave and Antes Creek haplotypes within the C. cognatus clade are identified by letters (A–D). Notice that cave individuals are found within both lineages. Despite being only 445 m apart, some haplotypes are present exclusively in cave individuals and not found in the Antes Spring population. Loose Tooth cave specimens had haplotype 2 and A.

  Part of: Espinasa L, Smith DM, Lindquist JM (2021) The Pennsylvania grotto sculpin: population genetics. Subterranean Biology 38: 47-63. https://doi.org/10.3897/subtbiol.38.60865