Phylogenetic Systematics of the Prickleback Family Stichaeidae (Cottiformes: Zoarcoidei) using Morphological Data

• Main Author: Clardy, Todd R.
• Format: Text
• Language: English
• Published: W&M ScholarWorks 2014
• Subjects: Zoology; Arctic; Pacific; North Atlantic; Pacific Arctic; Alaska
• Online Access: https://scholarworks.wm.edu/etd/1539616612; https://doi.org/10.25773/v5-fyer-5n47; https://scholarworks.wm.edu/context/etd/article/2180/viewcontent/3582016.pdf

The prickleback family Stichaeidae, as currently recognized, is a diverse group of small (<30 cm TL) eel- or blenny-like marine fishes distributed in intertidal, subtidal, and continental slope waters of the North Pacific, Arctic, and North Atlantic oceans. Stichaeidae is one of nine families within the Cottiformes suborder Zoarcoidei and includes six subfamilies, 38 genera, and about 80 species. However, there are questions regarding the monophyly of the family and its position within Zoarcoidei, due in part to a lack of fundamental descriptive anatomical data for the family. The first chapter of my dissertation describes the osteology of Xiphister, a genus of Stichaeidae that includes two species, X. atropurpureus and X. mucosus, found in intertidal and subtidal waters from southern Alaska to southern California. I describe and illustrate their skeletal anatomy, clarify aspects of their anatomy discussed by previous researchers, and describe for the first time elements such as the hyoid and gill arches, scales, and the development of their lateral line canals. These data establish a foundation for the further anatomical and systematic studies of Stichaeidae, and Zoarcoidei generally. Some members of Stichaeidae, including both species of Xiphister , have multiple lateral line canals on their trunk, which is a feature found in only 15 families of teleostean fishes. In the second chapter of my dissertation, the structure and ontogeny of lateral line canals of both species of Xiphister were studied using cleared & stained specimens and histology. Both species have seven cephalic canals and three paired canals on the trunk located on the dorsolateral, mediolateral, and ventrolateral body surfaces. The ventrolateral canal also includes a short loop across the ventral surface of the abdomen. The trunk canals and four short branches of the infraorbitals that extend across the cheek are supported by small ossified rings. The trunk canals develop asynchronously and separately from the development of scales, ...