Osteology of the Graveldiver Scytalina cerdale (Perciformes: Zoarcoidei: Scytalinidae)

The Graveldiver, Scytalina cerdale, is a small, poorly known burrowing fish from the intertidal and subtidal zones of the west coast of North America, ranging from south‐central California to Alaska. This is the sole member of the family Scytalinidae, which is included in the Zoarcoidei. Although it was described over 120 years ago, it is rare in natural history collections and its anatomy is only imperfectly known. This article describes and illustrates the skeletal anatomy of S. cerdale based on newly prepared cleared and stained specimens. Many points of its anatomy are clarified or corrected (e.g., presence of the intercalars and ribs, in contrast to their reported absence) or described for the first time (e.g., structure of its gill‐arches). Previous hypotheses of its systematic placement within the Zoarcoidei are discussed. On the basis of preliminary comparisons, S. cerdale may have phylogenetic affinity with at least some members of the family Stichaeidae (e.g., Xiphister). However, further study is needed on the anatomy and inter‐relationships of the families of the Zoarcoidei before any conclusions can be made. J. Morphol., 2009. © 2009 Wiley‐Liss, Inc.