DOI: 10.5061/dryad.k3j9kd5hx
title: African cichlid fish genera (Pseudocrenilabrinae): counts of vertebrae, supraneurals, dorsal and anal pterygiophores; pterygiophore insertion patterns

description: This is the first survey in cichlids of the considerable variation in
 numbers of vertebrae, supraneurals, and dorsal- and anal-fin supports
 (pterygiophores), as well as the patterns with which the pterygiophores
 insert between the neural or hemal spines. The study includes some 1700
 specimens of nearly 400 cichlid species. Focusing on the largest
 subfamily, the African cichlids or Pseudocrenilabrinae, the survey
 furnishes data from species in all but one of its 166 genera. Limited data
 from species in the other cichlid subfamilies (Etroplinae,
 Ptychochrominae, and Cichlinae) and from the related leaffishes,
 Polycentridae, are also presented. The character complex here surveyed is
 a promising source of taxonomically and phylogenetically informative
 characteristics distinguishing or uniting cichlid taxa at multiple
 hierarchical levels, from species through subfamily. This reference set of
 novel character data can also inform paleontological studies of African
 cichlids. These attributes are skeletal features potentially available for
 study in well preserved fossils and may help determine their correct
 taxonomic placement.
description: This study is based on data recorded from radiographs, microCT
 image stacks, and a few cleared-and-stained specimens. In all, data from
 1705 specimens of 391 cichlid species are included, representing all
 tribes within the African cichlid subfamily Pseudocrenilabrinae and
 exemplars of the other three cichlid subfamilies. Limited data from a few
 leaffishes (Polycentridae) are included for purposes of outgroup
 comparison. The primary type specimens (holotype or lectotype) of 90
 species are among the cichlid specimens included; their values are
 signaled in the supplementary spreadsheets/tables by an asterisk (*). At
 least one imaged specimen was available from 165 of the 166 currently
 recognized genera of Pseudocrenilabrinae. Only
 <em>Enigmatochromis </em>Lamboj, 2009 (Chromidotilapiini) is
 not represented. Film radiographs were scanned at a
 resolution of 1200 pixels per inch (ppi) and enlarged on a monitor and the
 raw meristic data and pterygiophore insertion patterns were recorded on a
 spreadsheet. For radiographs and microCT images available online, I
 enlarged the image on the monitor to fullscreen size and captured one or
 more screenshots, saved in .jpg format at 96 ppi. I later recorded
 meristic and pattern data while displaying each image on the monitor at
 sufficient enlargement to enable seeing all required small details,
 notably the supraneurals and the posterior dorsal and anal pterygiophores.
 If the specimen was not imaged with head to the left, I reversed the
 image. If the fish’s image was not approximately horizontal or adequately
 clear to permit reasonable certainty of interpretation, I rotated it or
 applied one or more digital enhancements in Corel PaintShop Pro X8
 18.3.0.13 x64. These techniques included sharpening with the unsharp mask,
 adjusting brightness and contrast, adding fill light, increasing image
 clarity, and applying local tone mapping (LTM). LTM proved particularly
 helpful in bringing out details on low-contrast images. A few images,
 especially those created from microCT volumes, could not be made usably
 clear because the small posterior pterygiophores were inadequately
 resolved in the original image stack. I did not use such images.
 The data were recorded on the spreadsheet
 (Table_S10_Raw_data.xlsx) as follows. Two successive rows are allocated
 for each specimen. The number of cells in the upper row, starting from the
 left (craniad), equals the total count of precaudal plus caudal vertebrae,
 including the compound terminal centrum. For a specimen with a count of
 13+16=29 vertebrae, a “c” is placed in column 29 of both rows. For the
 lower row, the first entry is placed below the cell of the first caudal
 vertebra. Thus, for a 13+16 count, a temporary “x” is placed in the second
 row column 14 (the precaudal count plus 1) to mark where the contents of
 the first insertion space immediately anterior to the first anal
 pterygiophore is to be entered.  The entry for each
 cell records the contents of the corresponding insertion space anterior to
 that centrum’s neural or hemal spine. In column 1 of the upper row an
 entry is made representing the first dorsal insertion space in front of
 the first neural spine. A separate “0” is entered for each supraneural; a
 numeral is entered to indicate the number of pterygiophores. If more than
 one element is present in a space, the elements are separated by hyphens.
 Thus, if the insertion space has two supraneurals and two pterygiophores,
 0-0-2 is recorded. The contents of each dorsal insertion space is
 similarly entered. An empty insertion space is indicated with a dash (–).
 The contents of the interhemal spaces are similarly entered in the lower
 of the two rows. The first (most anterior) anal pterygiophore(s) are
 situated either in the first anal insertion space (immediately in front of
 the first hemal spine), or the first space is empty and they occur in the
 second space (between first and second hemal spines), with a single
 exceptional genus: Uniquely in the Lake Tanganyikan genus
 <em>Cyprichromis</em>, five to seven anal pterygiophores are
 abdominal in position, located anterior to the first anal insertion space
 and inserting toward or between successive pairs of pleural ribs. These
 abdominal pterygiophores are indicated in Table_S10_Raw_data.xlsx by
 placement in gray-shaded cells. The analytical
 spreadsheets (Table_S1.xlsx through Table_S9.xlsx) demonstrate some of the
 possible ways of comparing the counts and insertion patterns in the raw
 data. The primary type specimens (holotype or lectotype) of 90 species are
 among the cichlid specimens included; their values are signaled by an
 asterisk (*).
description: # Data from: African cichlid fishes: morphological data and taxonomic
 insights from a genus-level survey of supraneurals, pterygiophores, and
 vertebral counts (Ovalentaria, Blenniiformes, Cichlidae,
 Pseudocrenilabrinae)
 [https://doi.org/10.5061/dryad.k3j9kd5hx](https://doi.org/10.5061/dryad.k3j9kd5hx) ## Description of the data and file structure These data were collected to learn the variation and taxonomic distribution of a suite of postcranial osteological characters in the African cichlid fishes. The features included in the data are counts of the vertebrae (precaudal, caudal, and total); counts of supraneurals; counts of dorsal and anal fin suports (pterygiophores); and insertion patterns of these supraneurals and pterygiophores relative to the neural spines or hemal spines of the vertebral column. ### Files and variables The following files are provided: * **Supplementary Materials.pdf**: Introduction to the data presentation, and sequence of taxa in all supplementary tables. This single file contains all of the following sections in .pdf form, individually linked from its first page (a table of contents). Clickable links at top left on the first page of each table or section provide rapid return to the contents page. The tables are also provided separately as Excel files for convenience in any reuse of the data: **Frequency distributions in Polycentridae (outgroup) and Cichlidae:** 1. Table_S1.xlsx: Vertebral counts 2. Table_S2.xlsx: Number of vertebrae behind the last occupied dorsal insertion space and last occupied interhemal space 3. Table_S3.xlsx: Total number of dorsal pterygiophores 4. Table_S4.xlsx: (1) Number of anal pterygiophores anterior to first hemal spine and (2) Total number of anal pterygiophores 5. Table_S5.xlsx: Number of dorsal pterygiophores minus anal pterygiophores 6. Table_S6.xlsx: Longest consecutive series of a single dorsal pterygiophore in each dorsal insertion space 7. Table_S7.xlsx: Insertion patterns of supraneural(s) and pterygiophores in the first three dorsal insertion spaces 8. Table_S8.xlsx: Pterygiophore insertion patterns in the last four occupied dorsal insertion spaces 9. Table_S9.xlsx: Pterygiophore insertion patterns in the last four occupied interhemal spaces \---------- * Table_S10_Raw_data.xlsx: Raw specimen-level data - Specimens examined and information sources.pdf See 'Methods' for more details on the contents of these files. ## Code/software Not applicable. ## Access information Data are derived from the following sources: * Physical film radiographs; * Digital radiographs requested and received from museums; * Digital radiographs publicly available via several museums' online collection catalogs; * microCT image stacks and radiographs available on MorphoSource. All image sources are given for each specimen in the file "Specimens examined and information sources.pdf."