1. related to Careproctus melanurus Gilbert 1892
Meristic evidence for a new snailfish (Scorpaeniformes: Liparidae) from the eastern North Pacific
related to Careproctus melanurus Gilbert 1892
Rachel Manning1 and James W. Orr2
1University of Washington Burke Museum Fish Collection, School of Aquatic and Fishery Sciences, and
2NOAA/National Marine Fisheries Service, Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, Seattle
Meristic evidence for a new snailfish (Scorpaeniformes: Liparidae) from the eastern North Pacific
related to Careproctus melanurus Gilbert 1982
Rachel Manning1 and James W. Orr2
1University of Washington Burke Museum Fish Collection, School of Aquatic and Fishery Sciences, and
2NOAA/National Marine Fisheries Service, Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, Seattle
We examined the following meristic characters: dorsal-fin, anal-fin, and caudal-fin rays, including anterior anal-fin pterygiophores, and precaudal, caudal, and total vertebrae, using digital radiography.
We observed an overall trend in increasing mean counts with increasing latitude by region (Table 1). Highly significant differences and minimally overlapping ranges in meristics were found between Alaskan and west coast Careproctus melanurus. Alaska specimens had significantly higher mean median fin-ray and vertebral counts than west coast specimens from Washington to California; anterior anal-fin pterygiophore and precaudal vertebrae counts did not differ (Table 2).
The genus Careproctus presently comprises about 140 species worldwide, with many undescribed species identified regularly. Ranging from northern Japan to Baja California, C. melanurus, the Blacktail Snailfish, is among the most commonly collected liparids in the eastern North Pacific at depths of 200 m or greater.
Careproctus melanurus, California
Table 2. Summary of meristic characters for Careproctus sp. cf. melanurus and Careproctus melanurus used for statistical analyses as evaluated by a two-sample t-test. ns = not statistically significant. n = number of specimens sampled.
Table 1. Frequency distributions of median-fin ray counts, vertebral counts (caudal, pre-caudal, and total), and anterior anal pterygiophore counts. BS = Bering Sea, GOA = Gulf of Alaska, N. CA. = Northern half of California, S. CA = Southern half of California. * = denotes count bins in which some specimens have available genetic data.
Careproctus sp. cf. melanurus, Bering Sea
We collected meristic data from 51 specimens identified as C. melanurus from Alaska and the west coast south of British Columbia (Fig. 1). About 10 specimens were selected from each major geographic area: the Bering Sea, Gulf of Alaska, Washington, Oregon, and California. All specimens were collected by NOAA’s Alaska Fisheries Science Center (AFSC) as part of resource assessment surveys and are maintained in the University of Washington Burke Museum Fish Collection.
This meristic evidence augments genetic data that initially suggested the presence in Alaska of a new species closely related to Careproctus melanurus. The distribution of the two species correlates with the two eastern North Pacific zoogeographic provinces—the Aleutian to the north and Oregonian to the south— within which relatively high rates of species endemism are observed. The transition between the two provinces is along Vancouver Island and the Salish Sea, from where we lack specimens.
Our material of Careproctus sp. cf. melanurus was collected from the central Bering Sea to Southeast Alaska (59°N–54°N; Fig. 1). It likely occurs throughout the Aleutian province to a southern boundary near 50°N, while Careproctus melanurus may be limited to the northern boundary of the Oregon province, ranging southward to Baja California. Additional meristic and morphometric data is currently being collected and new material from British Columbia is being examined. Because the type locality of Careproctus melanurus is off southern California, the Alaska species will receive a new name.
Gardner et al. (in press)
A study of snailfish eggs found in lithodid crabs in Alaska using COI sequence data suggested the presence of an unidentified liparid closely related to Careproctus melanurus when sequences of several egg masses matched none of the sequences of 23 species initially compared for identification. Among those with no match was C. melanurus, previously recorded as the most common species found in eggs deposited in lithodids. However, because C. melanurus was represented by a single individual from Washington, additional sequence data from Alaska vouchers was added, which matched the egg sequences. Sequence data between Washington and Alaska specimens of C. melanurus differed by at least 4%. Therefore, we hypothesized that specimens identified as C. melanurus in Alaska represented an undescribed species.
Acknowledgments—We thank J. Gardner and I. Spies for genetic data, and D. Stevenson, K. Maslenikov, and T. Pietsch for discussions, collections support, and reviews.
Figure 1. Collection sites of 51 reviewed specimens. Each symbol may represent more than one individual. Green = Careproctus sp. cf. melanurus; Orange = Careproctus melanurus.
Comments and conclusions presented in this poster do not necessarily represent the views or official positions of the Department of Commerce, National Oceanic and Atmospheric Administration, or the National Marine Fisheries Service.