OCCURRENCE OF A RATFISH 

 IN THE COLUMBIA RIVER ESTUARY 



A ratfish, Hydrolagus colliei (Lay and Bennett), 

 was captured in the Columbia River estuary, near 

 the Oregon shore, on 24 August 1972. Commercial 

 fishermen Howard and Mark Simonsen captured 

 the specimen near buoy 21, approximately 8 km 

 upstream from the mouth of the river. They were 

 fishing for salmon in 8 m of water with a dacron 

 gillnet of 8 %-inch mesh and an effective fishing 

 depth of between 10 and 12 m. The fish was caught 

 at 2030 h during an incoming tide; the actual 

 depth, temperature, and salinity at place of cap- 

 ture are unknown. At the time of capture, how- 

 ever, our monitoring station, 3.2 km farther up- 

 stream, indicated a water temperature of 13.4''C 

 and a salinity of bYco at a depth of 10 m. The 

 salinity was increasing and reached 31 /{o 5 h 

 later. The ratfish was an adult male, 445 mm in 

 length, weighing 460 gm (Figure 1). There are no 

 known methods of determining the ages of 

 chimaeroids, including the ratfish (Simmons and 

 Laurie, 1972). The specimen was preserved and is 

 now part of the collection at the facility of the 

 Northwest Fisheries Center, National Marine 

 Fisheries Service, at Hammond, Greg. Although 

 ratfish are distributed along the coast of western 

 North America from southeastern Alaska to Baja 

 California, including the upper Gulf of California 



(Hart, 1973), this is the first record of one appear- 

 ing in the Columbia River estuary. In fact, no 

 chimaeroid has been recorded from any estuarine 

 water (Carl L. Hubbs, Scripps Institution of 

 Oceanography, University of California at San 

 Diego, La Jolla, CA 92037, pers. commun). 



"Hydrolagus colliei is the only species of chi- 

 maera reported from the west coast of the United 

 States, and, unlike other species in the family, it 

 generally inhabits relatively shallow water." 

 (Halstead, 1970). According to Hart ( 1973), ratfish 

 ai-e common visitors to shallow Canadian waters 

 but are most abundant at 92 to 275 m in inside 

 waters and at 183 to 366 m in outside waters. He 

 also reports that they are "in deeper water toward 

 the south (as in northern California)". The occur- 

 rence in the deeper water toward the south is real 

 and significant, but they may not occur in deeper 

 waters off northern California because that is an 

 area of extremely cold ocean temperatures (Carl 

 L. Hubbs, pers. commun.). Day and Pearcy (1968) 

 captured ratfish off the Oregon coast at depths 

 between 40 and 200 m. Ratfish are weak swim- 

 mers, mostly noctural in behavior, but have been 

 seen swimming at the surface in southeastern 

 Alaska and British Columbia waters (Goode and 

 Bean, 1895). 



Maximum spawning activity is in late summer 

 and early fall (Sathyaneson, 1966). On 26 June 

 1957, a large concentration of ratfish became 



Figure 1. — Ratfish, /f>'£/ro/agi/s colliei, captured in the Columbia River estuary. 



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