Clear Lake hitch

Local Pomo Tribes call Clear Lake hitch "chi" and harvested the fish during its spawning runs.

Juveniles are silver with a dark spot on their caudal peduncle that extends towards the head in the form of a black stripe that gradually fades.

Adults no longer have the dark spot on their caudal peduncle and have become duller in color with the dorsal area turning brownish-yellow.

It has been proposed that juveniles stay in nearshore habitats because it offers protection from predation by largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus), both of which are non-native fish.

Meanwhile, adult hitch live a nomadic, planktivorous lifestyle, resulting in them having a larger habitat range than juveniles.

[16] During this time period, the streams are flooded by water from the seasonal rains due to the local Mediterranean climate.

Juvenile hitch between 19–30 mm standard length feeds primarily on larvae and pupae of chironomid midges.

[3] Juveniles are also seen feeding on planktonic crustaceans, which include Bosmina and Daphnia, plus the eggs, larvae, and adults of the Clear Lake gnat (Chaoborus astictopus).

In an experiment, hitch caught in the afternoon had something in their stomachs; based on the observations, the researchers determined that they feed during the daytime.

The water from the rains gives them a window to migrate, spawn, larval development to occur, and allow juveniles to emigrate to the lake.

However, since the rivers fill up seasonally, there is a limited time period that allows spawning, young to develop, then emigrate back to the lake before the stream dries up.

[17] It takes 120 hours after fertilization for the embryo to show a red spot, which is the heart, dorsal, anal, and caudal fin folds; pigment is visible in the eyes, making them appear sooty.

[16] One non-native fish species that established a large population in Clear Lake is the Mississippi silversides (Menidia audens); it was introduced in 1967.

Ten years after the introduction of the silversides, research was conducted to see if the Clear Lake hitch was impacted by the non-native fish.

[9] It was discovered that Clear Lake hitch's diet or growth rates weren't impacted by the introduced fish.

Hitch avoided competing with the non-native fish by inhabiting inshore areas during spring to early summer when silverside populations were low.

[20] Dams and structures delay spawning, which can result in adults and/or developing young becoming stranded in the drying streams.

[21] Pugheadedness is a deformity in the skeleton resulting in a steep forehead, bulging eyeballs, and a reduced upper maxillary.

Fish that survive to adulthood have decreased fitness due to reduced foraging efficiency and inefficient respiration.

[21] Speculated causes of pugheadedness are the genes changing due to environmental factors such as pollution, continuous low concentrations of dissolved oxygen, and high water temperatures.

[22] Members from the Pomo Tribe would hand-harvest and process Clear Lake hitch into fish jerky, which provided them a year-long sustenance.

In 2022, Interior Secretary Deb Haaland was urged to use her emergency powers and invoke the federal Endangered Species Act on behalf of the Clear Lake hitch.

Fig.1 A proposed taxonomic hierarchy of the Hitch and Roach from the data that used RAD DNA sequencing. [ 8 ]
Fig. 5 The distribution of juvenile and adult Clear Lake Hitch in Clear Lake during the summer. [ 13 ]
Fig. 13 Embryonic development of Clear Lake hitch. [ 17 ]
Fig. 14 The early development stages of Clear Lake hitch after hatching. [ 17 ]
Fig. 15 A map of the physical passage barriers that impact the Clear Lake hitch. [ 18 ]
Fig. 16 The pugheaded Clear Lake hitch that was collected in 2017. [ 21 ]
Fig. 17 The pugheaded Clear Lake hitch (fish on the bottom) that was collected in 2019 compared to a normal Clear lake hitch (fish on the top). [ 21 ]