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University of California

California Fish Website

 Fish Sacramento Splittail

 Scientific Name Pogonichthys macrolepidotus

 Native Native Species

California Fish Species - California Fish Website http://calfish.ucdavis.edu/species/?uid=83&ds=241

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 Identification

Sacramento splittail, juvenile , approximately 10 cm (4”) long. Location: Suisun

Marsh, California. Date: 8/6/2007.

Sacramento splittail, adult, from the Cosumnes River, CA. Photo courtesy of

Professor Peter B. Moyle.

Large minnow, to over 40 cm SL

Oversized upper lobe of caudal fin, elongate body, adults with hump

Slightly sub-terminal mouth, barbels present at margins

Hooked pharyngeal teeth, tiny inner-tooth row

Coloration: silver, fading with age, dusky olive gray back

Breeding adults: caudal, anal, dorsal, and paired fins have red-orange tinge

Breeding males: darker than normal, white tubercles on head and bases of fins

Fin rays: dorsal 9-10, pectoral 16-19, pelvic 8-9, anal 7-9

Lateral line scales: 57-64

California Fish Species - California Fish Website http://calfish.ucdavis.edu/species/?uid=83&ds=241

2 of 3 4/21/2016 11:25 AM
 Life History

Sacramento splittail are hearty minnows that live in fluctuating environments and can

tolerate relatively high salinities and low oxygen levels (< 1.0 mg/L). Typically they are

found in estuarine environments and are commonly found in water with salinities from

10-18 ppt. They prefer slightly lower salinities but can survive short term exposures to

water with a salinity as high as 29 ppt. Splittail are usually found where water

temperatures range from 5-24°C, though under laboratory conditions they have shown an

ability to survive short exposures to temperatures as high as 33°C. These adaptations

make splittail well suited for slow moving rivers, sloughs, and alkaline lakes. Sacramento

splittail feed on bottom dwelling invertebrates and detritus in low to moderate currents.

Young splittail focus their feeding on benthic crustaceans and they show an ability to

swim against strong tides and currents. In the Sacramento-San Joaquin Delta splittail

feed opportunistically during the day with peak feeding early in the morning. Prey items

include clams, crustaceans, insect larvae, and other invertebrates. During high flows they

may enter the floodplain where they feed on earthworms. In the Suisun Marsh opossum

and then mysid shrimp have been focal points of feeding for the splittail. Sacramento

splittail live relatively long lives of up to 5-7 years, possibly longer. Females live longer

than males and reach greater total lengths. Splittail typically reach sexual maturity by the

end of their second year (around 170 mm SL). Males may mature in their first year (110 m

SL) while females may not mature until their third year (215 mm SL). After their third year

splittail grow an average of 35 mm/year for the remainder of their life. During winter and

spring adult splittail move upstream to forage and later spawn between late February and

early July. Spawning is presumably triggered by day length, increased flows, and water

temperatures rising to a range of 14-19°C. Spawning occurs in flooded vegetation with

older fish spawning first. Peak reproduction occurs in March and April though splittail are

fractional spawners, so the process may take months. Typically egg production increases

with body size and one large female may produce over 100,000 eggs. Fertilized eggs

stick to the flooded vegetation till the embryos hatch 3-7 days later. Hatch time is

temperature dependent. Active feeding and swim bladder function in the larvae begins

5-7 days after the hatch. The larvae remain in the vegetation for 10-14 days where they

have adequate cover and access to small prey. Young-of-year splittail move into the

estuary in April-August where they occupy water less than 2 m deep.

 Watershed Coyote Watershed, Lower American Watershed, Lower Bear Watershed, Lower

Feather Watershed, Lower Sacramento Watershed, Lower Yuba Watershed,

Middle San Joaquin-Lower Chowchilla Watershed, Middle San Joaquin-Lower

Merced-Lower Stanislaus Watershed, Sacramento-Stone Corral Watershed, San

Joaquin Delta Watershed, San Pablo Bay Watershed, Suisun Bay Watershed

Please note, watersheds are at the USGS 8-digit Hydrologic Unit Code (HUC) scale, so they often

include a lot of sub-watersheds. If a species occurs in any sub-watershed within the HUC, the

species appears within the HUC. Link to an EPA page that shows HUCs.

Webmaster Email: mailto:rfkeiffer@ucanr.edu?subject=CalFish Website Query

California Fish Species - California Fish Website http://calfish.ucdavis.edu/species/?uid=83&ds=241

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