Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed
The rapid decline of longfin smelt <i>Spirinchus thaleichthys</i>, a threatened euryhaline forage fish in California, is a serious concern for scientists and resource managers. To recover and conserve this species, a captive culture program was initiated, focusing on the collection, capt...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-06-01
|
| Series: | Animals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-2615/12/12/1478 |
| _version_ | 1797490735928311808 |
|---|---|
| author | William Mulvaney Md Moshiur Rahman Levi S. Lewis Jiayi Cheng Tien-Chieh Hung |
| author_facet | William Mulvaney Md Moshiur Rahman Levi S. Lewis Jiayi Cheng Tien-Chieh Hung |
| author_sort | William Mulvaney |
| collection | DOAJ |
| description | The rapid decline of longfin smelt <i>Spirinchus thaleichthys</i>, a threatened euryhaline forage fish in California, is a serious concern for scientists and resource managers. To recover and conserve this species, a captive culture program was initiated, focusing on the collection, captive rearing and breeding of wild broodstock, and the rearing of their offspring. Although progress has been made in the collection of broodstock and the production and culturing of larvae, no studies have evaluated the rearing of juvenile life stages in captivity. The present study examines methodological considerations for culturing F1 juvenile longfin smelt, specifically, the first efforts toward weaning juveniles to a dry commercial pellet feed. Cultured juvenile longfin smelt were fed live <i>Artemia</i> only or co-fed <i>Artemia</i> and dry feed for 62 days, and the effects of feed type on juvenile survival, growth, body condition, and fatty acid profiles were examined. No significant differences were observed between feeding treatments, despite an 80% reduction in <i>Artemia</i> in the co-feeding treatment. Furthermore, examination of fish stomach contents at the end of the trial confirmed the transition to dry feed. This is the first study to indicate successful feeding by longfin smelt on dry commercial pellets, and suggests that juvenile longfin smelt can be fully weaned onto dry feeds. Results of this study are critical for closing the lifecycle of longfin smelt in captivity and developing a successful conservation culture program for this imperiled species. |
| first_indexed | 2024-03-10T00:37:51Z |
| format | Article |
| id | doaj.art-5b8b9e0ec1684955b0b7185a803210ae |
| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-03-10T00:37:51Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj.art-5b8b9e0ec1684955b0b7185a803210ae2023-11-23T15:13:46ZengMDPI AGAnimals2076-26152022-06-011212147810.3390/ani12121478Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry FeedWilliam Mulvaney0Md Moshiur Rahman1Levi S. Lewis2Jiayi Cheng3Tien-Chieh Hung4Fish Conservation and Culture Laboratory, Department of Biological and Agricultural Engineering, University of California, 17501 Byron Hwy, Byron, Davis, CA 94514, USAFish Conservation and Culture Laboratory, Department of Biological and Agricultural Engineering, University of California, 17501 Byron Hwy, Byron, Davis, CA 94514, USAOtolith Geochemistry and Fish Ecology Laboratory, Department of Wildlife, Fish and Conservation Biology, University of California, 1088 Academic Surge, Davis, CA 95616, USAFish Conservation and Culture Laboratory, Department of Biological and Agricultural Engineering, University of California, 17501 Byron Hwy, Byron, Davis, CA 94514, USAFish Conservation and Culture Laboratory, Department of Biological and Agricultural Engineering, University of California, 17501 Byron Hwy, Byron, Davis, CA 94514, USAThe rapid decline of longfin smelt <i>Spirinchus thaleichthys</i>, a threatened euryhaline forage fish in California, is a serious concern for scientists and resource managers. To recover and conserve this species, a captive culture program was initiated, focusing on the collection, captive rearing and breeding of wild broodstock, and the rearing of their offspring. Although progress has been made in the collection of broodstock and the production and culturing of larvae, no studies have evaluated the rearing of juvenile life stages in captivity. The present study examines methodological considerations for culturing F1 juvenile longfin smelt, specifically, the first efforts toward weaning juveniles to a dry commercial pellet feed. Cultured juvenile longfin smelt were fed live <i>Artemia</i> only or co-fed <i>Artemia</i> and dry feed for 62 days, and the effects of feed type on juvenile survival, growth, body condition, and fatty acid profiles were examined. No significant differences were observed between feeding treatments, despite an 80% reduction in <i>Artemia</i> in the co-feeding treatment. Furthermore, examination of fish stomach contents at the end of the trial confirmed the transition to dry feed. This is the first study to indicate successful feeding by longfin smelt on dry commercial pellets, and suggests that juvenile longfin smelt can be fully weaned onto dry feeds. Results of this study are critical for closing the lifecycle of longfin smelt in captivity and developing a successful conservation culture program for this imperiled species.https://www.mdpi.com/2076-2615/12/12/1478Osmeridaeex situ conservationdietfatty acidsanadromous fish |
| spellingShingle | William Mulvaney Md Moshiur Rahman Levi S. Lewis Jiayi Cheng Tien-Chieh Hung Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed Animals Osmeridae ex situ conservation diet fatty acids anadromous fish |
| title | Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed |
| title_full | Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed |
| title_fullStr | Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed |
| title_full_unstemmed | Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed |
| title_short | Captive Rearing of Longfin Smelt <i>Spirinchus thaleichthys</i>: First Attempt of Weaning Cultured Juveniles to Dry Feed |
| title_sort | captive rearing of longfin smelt i spirinchus thaleichthys i first attempt of weaning cultured juveniles to dry feed |
| topic | Osmeridae ex situ conservation diet fatty acids anadromous fish |
| url | https://www.mdpi.com/2076-2615/12/12/1478 |
| work_keys_str_mv | AT williammulvaney captiverearingoflongfinsmeltispirinchusthaleichthysifirstattemptofweaningculturedjuvenilestodryfeed AT mdmoshiurrahman captiverearingoflongfinsmeltispirinchusthaleichthysifirstattemptofweaningculturedjuvenilestodryfeed AT levislewis captiverearingoflongfinsmeltispirinchusthaleichthysifirstattemptofweaningculturedjuvenilestodryfeed AT jiayicheng captiverearingoflongfinsmeltispirinchusthaleichthysifirstattemptofweaningculturedjuvenilestodryfeed AT tienchiehhung captiverearingoflongfinsmeltispirinchusthaleichthysifirstattemptofweaningculturedjuvenilestodryfeed |