DOI: 10.5061/dryad.cg3c5r5
title: Data from: Comparative morphology and evolution of the cnidosac in Cladobranchia (Gastropoda: Heterobranchia: Nudibranchia)

description: Background: A number of shelled and shell-less gastropods are known to use
 multiple defensive mechanisms, including internally generated or
 externally obtained biochemically active compounds and structures. Within
 Nudipleura, nudibranchs within Cladobranchia possess such a special
 defense: the ability to sequester cnidarian nematocysts – small capsules
 that can inject venom into the tissues of other organisms. This ability is
 distributed across roughly 600 species within Cladobranchia, and many
 questions still remain in regard to the comparative morphology and
 evolution of the cnidosac – the structure that houses sequestered
 nematocysts (called kleptocnides). In this paper, we describe cnidosac
 morphology across the main groups of Cladobranchia in which it occurs, and
 place variation in its structure in a phylogenetic context to better
 understand the evolution of nematocyst sequestration. Results: Overall, we
 find that the length, size and structure of the entrance to the cnidosac
 varies more than expected based on previous work, as does the structure of
 the exit, the musculature surrounding the cnidosac, and the position and
 orientation of the kleptocnides. The sequestration of nematocysts has
 originated at least twice within Cladobranchia based on the phylogeny
 presented here using 94 taxa and 409 genes. Conclusions: The cnidosac is
 not homologous to cnidosac-like structures found in Hancockiidae.
 Additionally, the presence of a sac at the distal end of the digestive
 gland may have originated prior to the sequestration of nematocysts. This
 study provides a more complete picture of variation in, and evolution of,
 morphological characters associated with nematocyst sequestration in
 Cladobranchia.
description: 16S final data
 matrixNEXUS file with the 16S
 alignment, with 88 taxa (length 492 bp). The MrBayes block is
 included.16S_con_cds_modified.nexCOI final data matrixNEXUS file with the COI alignment, with 86 taxa (length 683 bp). The MrBayes block is included.COI_con_cds_modified.nex18S final data matrixNEXUS file with the 18S alignment, with 83 taxa (length 4679 bp). The MrBayes block is included.18S_con_cds_modified.nexfull raxml data matrixFASTA file with the concatenated individual orthologous group alignments (409 total), with 94 taxa.full_raxml_cladobranchia.fa16S consensus treeConsensus tree from MrBayes run using the 16S final data matrix.16S_con_cds_modified.nex.con.out.treCOI consensus treeConsensus tree from MrBayes run using the COI final data matrix.COI_con_cds_modified.nex.con.out.tre18S consensus treeConsensus tree from MrBayes run using the 18S final data matrix.18S_con_cds_modified.nex.con.out.trefull unpartitioned raxml treeBest tree with bootstraps from RAxML run using the full raxml data matrix. This analysis was unpartitioned.full_raxml_cladobranchia.out.trethree gene final data matrixNEXUS file with the three gene alignment (COI, 16S, and 18S), with 94 taxa (length 5854 bp).clad_3_OGs_taxrem_fixed.nexthree genes consensus treeConsensus tree from MrBayes run using the three genes final data matrix.clad_3_OGs_taxrem_fixed.nex.con.out.tre