Sacramento Pikeminnow Ptychocheilus grandis is a potamodromous species endemic to mid- and low-elevation streams and rivers of Central and Northern California. Adults are known to undertake substantial migrations, typically associated with spawning, though few data exist on the extent of these migrations. Six Sacramento Pikeminnow implanted with passive integrated transponder tags in the Sacramento–San Joaquin Delta were detected in Cottonwood and Mill creeks, tributaries to the Sacramento River in Northern California, between April 2018 and late February 2020. Total travel distances ranged from 354 to 432 km, the maximum of which exceeds the previously known record by at least 30 km. These observations add to a limited body of knowledge regarding the natural history of Sacramento Pikeminnow and highlight the importance of the river–estuary continuum as essential for this migratory species.
Animals across a range of taxa engage in migratory behaviors as an important aspect of their life histories (Dingle 2014). Potamodromy, which is a type of migration that occurs entirely within freshwater, is a key strategy for inland fishes (Thurow 2016). Migratory behavior of potamodromous fishes results from an ontogenetic separation of optimal habitats for growth, survival, and reproduction (Northcote 1984). Although potamodromous fishes are widespread across the globe, potamodromy is far less studied than diadromy, whereby individuals migrate between freshwater and marine habitats (Northcote 1998). Migratory species are particularly susceptible to habitat loss, as they require multiple habitats across ontogeny and corridors connecting those habitats (Runge et al. 2014). Thus potamodromous fishes as a group are relatively imperiled, largely due to decreasing connectivity in freshwater environments (Thurow 2016).
Pikeminnows, genus Ptychocheilus within Cyprinidae, are fishes that can exhibit potamodromy native to western North America. There are four species in the genus: Colorado Pikeminnow P. lucius, inhabiting the Colorado River basin; Sacramento Pikeminnow P. grandis (Figure 1), endemic to California's inland waters; Northern Pikeminnow P. oregonensis, wide-ranging in the Pacific Northwest; and Umpqua Pikeminnow P. umpquae, native to the Umpqua and Siuslaw rivers (Carney and Page 1990; Moyle 2002). The pikeminnows are distinct among North American cyprinids because of adaptations for carnivorous feeding (Carney and Page 1990) and are often a major predator in their respective systems, especially before the introduction of nonnative piscivores (Moyle 2002). Pikeminnows often migrate from estuaries, lakes, and main-stem rivers to tributary streams in the spring and early summer to spawn (Moyle 2002). Some of these migrations can be quite extensive; Tyus (1990) tracked the movements of 63 adult Colorado Pikeminnow to spawning areas and observed average migrations of 140.7 km (range 32–372.8 km) in the Green River basin.
Sacramento Pikeminnow, the only Ptychocheilus endemic to California, are large bodied and long lived (Moyle 2002). Sacramento Pikeminnow historically obtained sizes of more than 900 mm (Gobalet and Fenenga 1993), and the largest contemporary Sacramento Pikeminnow on record measured 1,150 mm (standard length) and weighed 14.5 kg (Moyle 2002). A 662-mm Sacramento Pikeminnow from the Russian River was aged at 16 y using opercular bones, with larger fish likely older (Scoppettone 1988). They are naturally distributed across Central and Northern California in mid- and low-elevation streams and rivers of the Sacramento–San Joaquin system as well as the Clear Lake basin, the Salinas and Pajaro rivers, the Russian River, and upper Pit River (Moyle 2002). Sacramento Pikeminnow are still common throughout their range but have become less abundant in lowland habitats (Moyle 2002). They are thought to make long migrations on the basis of fortuitous information and direct observations of closely related species. For example, Tucker et al. (1998) noted Sacramento Pikeminnow migrations of up to 378.4 km in the Sacramento River on the basis of public angler recaptures. Here we report observations of migration distance records for six Sacramento Pikeminnow tagged in the Sacramento–San Joaquin Delta and detected in tributaries of the upper Sacramento River.
Methods and Results
In the course of various research projects in the tidal northern Sacramento–San Joaquin Delta, we implanted six individual adult Sacramento Pikeminnow with passive integrated transponder tags (data available from Steinke et al. 2019). We observed tagged individuals in PIT-tag antenna arrays located in the upper Sacramento River tributaries of Cottonwood and Mill creeks, two undammed streams with relatively good habitat for native fishes (Figure 2; Table 1). We calculated migration distances (km) of tagged and subsequently detected fishes using the Google Earth Pro (version 7.3.2) path tool. We generated paths along the shortest distance within waterways from tagging location in the Sacramento–San Joaquin Delta to the confluence of Cache Slough and the Sacramento River, then following the main-stem Sacramento River to either Cottonwood Creek or Mill Creek and along the tributary to the PIT tag antenna array where we detected the individual (Figure 2).
We tagged the six Sacramento Pikeminnow (no. 1–6) between February 2017 and November 2018 across the northern Sacramento–San Joaquin Delta, including Lindsey Slough (no. 1), the Sacramento Deepwater Shipping Channel (no. 2, 5), the Southern Yolo Bypass (no. 3), Cache Slough (no. 4), and Liberty Island (no. 6). We detected five fish (no. 1, 3, 4, 5, 6) in Cottonwood Creek and one fish (no. 2) in Mill Creek. All detections occurred between late February and early May 2018–2020. Distances traveled from tagging location to detection location ranged between 354 and 432 km and fish were at large between 69 and 745 d (Figure 2; Table 1).
These observations of the volitional distance traveled by Sacramento Pikeminnow exceed the previously documented record (400 km; Moyle 2002) by as much as 32 km. Timing of the detections in Cottonwood and Mill creeks is consistent with the known spawning period of Sacramento Pikeminnow (Grant and Maslin 1999; Bettelheim 2001), suggesting that the observed movements were in part spawning migrations. The movements of fish 1, which traveled 424 km in 69 d, provide the most direct observation of a presumed spawning migration. Assuming it initiated migration immediately upon tagging and that we detected it as soon as it arrived in Cottonwood Creek, this would indicate that it traveled approximately 6 km/d during its spawning migration.
In the genus Ptychocheilus, the most comparable migrations are undergone by Colorado Pikeminnow, with individuals migrating long distances to natal streams for spawning (Tyus 1990; McAda and Kaeding 1991; Irving and Modde 2000). The upper extent of migration distances for both species is similar; when factoring for distance traveled from tagging location to spawning grounds, Colorado Pikeminnow migrations range between 218 and 476 km (Irving and Modde 2000), compared with our observations of 354–432 km for Sacramento Pikeminnow. However, the maximum distances migrated by Colorado Pikeminnow may have been greater before regulation of the Colorado River and its tributaries (McAda and Kaeding 1991; Irving and Modde 2000). Migration timing of the two pikeminnows shows little overlap, with Sacramento Pikeminnow migrating to spawning sites in February through May (Grant and Maslin 1999; Bettelheim 2001) and Colorado Pikeminnow migrating from mid-May through August (Tyus 1990; McAda and Kaeding 1991; Irving and Modde 2000). However, the major factor that stimulates migration for both species appears to be changes in discharge (Tyus 1990; Grant and Maslin 1999; Bettelheim 2001), which differs between the two watersheds, with Colorado Pikeminnow also showing responses to temperature and photoperiod (Tyus 1990).
A lack of basic natural history information and limited understanding of the scale and timing of migratory behavior have been identified as key uncertainties limiting the effectiveness of freshwater fish conservation (Cooke et al. 2012). The observations detailed here add to the limited body of knowledge regarding the natural history of Sacramento Pikeminnow and their migrations. As such, they highlight the importance of the river–estuary continuum as essential for migratory populations of Sacramento Pikeminnow. Further research into migration patterns and habitat use of Sacramento Pikeminnow and other migratory native fishes can help resource managers develop strategies to prioritize connectivity in increasingly fragmented systems.
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Reference S1.Bettelheim M. 2001. Temperature and flow regulation in the Sacramento River and its effect on the Sacramento pikeminnow (Ptychocheilus grandis). A literature review. California Department of Fish and Game, Central Valley Bay-Delta, Stockton, USA.
Found at DOI: https://doi.org/10.3996/JFWM-20-038.S1 (129 KB PDF).
Reference S2.Tucker ME, Williams CM, Johnson RR. 1998. Abundance, food habits and life history aspects of Sacramento squawfish and striped bass at the Red Bluff Diversion Complex, including the Research Pumping Plant, Sacramento River, California, 1994–1996. Red Bluff Research Pumping Plant Report Series, Volume 4. U.S. Fish and Wildlife Service, Red Bluff, California.
Found at DOI: https://doi.org/10.3996/JFWM-20-038.S2 (2.1 MB PDF).
The Bureau of Reclamation (Interagency Agreement No. R15PG00085) provided funding for projects that made these observations possible. Tremendous thanks to Thomas Clifford, Brian Poxon, Ryan Revnak, and the California Department of Fish and Wildlife Central Valley Steelhead Monitoring Program for informing us of these detections as well as their continued coordination with our project. Thanks to the field crews who captured and tagged the fish, including Ethan Clark, Justin Clause, Ethan Enos, Mary Jade Farruggia, Emerson Gusto, Jesse Kathan, Veronica Larwood, Oliver Patton, and Robert Spankowski. Thanks to David Ayers for valuable discussion.
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Citation: Valentine DA, Young MJ, Feyrer F. 2020. Sacramento Pikeminnow migration record. Journal of Fish and Wildlife Management 11(2):588–592; e1944-687X. https://doi.org/10.3996/JFWM-20-038
The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service.