With their aggressive feeding habits and spectacular colorsolive-green backs, white-tipped fins, a spattering of yellow and red spots ringed in pale blue and fire-red belliesbrook trout are arguably one of the most attractive sport fish in North America.
But while regarded as an iconic predator in their native rangethat is, cool, well-oxygenated lakes and streams in the eastern U.S. and Canada, from northern Georgia up to the Hudson Baythe fish are an unwelcome presence in the Western U.S.
Thats for two reasons, according to Gregg Anderson, Idaho Fish and Game Hatchery Manager for the Magic Valley region. Ever since brook trout were first introduced in the West in the early 1900s to expand fishing opportunities, he said theyve taken over high mountain lakes throughout central and eastern Idaho, particularly in the Big Lost region near Mackay.
The fish are so abundant that they have threatened native cutthroat and bull trout populations. And while they can reach over 20 inches in captivity, Anderson said, overpopulation limits them to much smaller sizes in the wild. The stunting effect makes them unappealing to anglers, Anderson noted.
The YY super-males selected for breeding are chemically drugged in large white plastic bins. As their thrashing movements becoming more sluggish, a fishery technician (pictured: Hannah Zigman) dries the belly of a fish with a towel, massages its belly and collects milt in a plastic bag. The same process is used for collecting eggs from female brook trout.
They are an introduced, prolific species from the Eastern Seaboard that did better than they should have, Anderson said. What happens is that theyll overpopulate and cut out what is supposed to be in our streamscutthroat trout, bull trout and rainbow trout.
In the early 2010s, biologists at the Idaho Department of Fish and Game began brainstorming solutions to eradicate the non-native fish. A few possible solutions were introducing tiger musky or tiger trout in alpine lakes, chemically treating the lakes to kill all fish present or enlisting fishermen to catch and cull brook trout one by one. But none of those methods were efficient or cost-effective. So, in 2013, the department established its YY Male Brook Trout Research Program to collapse the population in a more sustainable, less invasive manner.
The goal is simple: to skew the ratio of males to females by intentionally creating super male trout that can only produce male offspring. The super-males have two Y chromosomes instead of the usual XY arrangement and are created through selective breeding, Anderson explained.
This is a first-in-the-world program.
Gregg Anderson
Hatchery Manager, Idaho Fish and Game
The hope is that eventually, the unwanted fish population--infiltrated with YY males--will produce fewer and fewer females and die off.
Since 2015, when Hayspur Hatchery technicians first began rearing YY brook trout, the project has excited fish biologists and fishery managers around the world, Anderson said. If proven successful, the methodology could be used to target problematic non-native fish populations in the Eastern U.S., such as Asian carp that have infiltrated the Mississippi River and surrounding waters.
Hayspur Hatchery Fishery Technician Paula Fanta uses eyedropper to collect ovarian fluid from brook trout eggs. Any bad batches with bacteria detected are culled, while good batches are placed in a cooler to await fertilization. The eggs are then shipped to other hatcheries across the country.
Located south of Bellevue in Blaine County, the Hayspur State Fish Hatchery was established in 1907 and began rearing trout in the early 1920s. Today, the facility produces anywhere from 6 to 7 million trout annually.
The campus is large, with an incubation building for trout eggs, a hatchery building with rearing vats, an office building, steel silos, and 10 raceways, or concrete channels.
On a particular Tuesday in October, hatchery technicians scoop pellets out of a large 5-gallon bucket and distribute them in one of the facilitys rainbow trout raceways, covered with steel wire to bar fish-eating herons, pelicans and mink from entering. (Regulations are strict and all waters must be kept disease-free. If a feral cat gets into one of the raceways, for example, all fish in the channel must be culled.)
Nearby, brook trout are housed in large bins and circular ponds enclosed by steel silos, one for each age group: first-years, second-years, third-years and fourth-years.
In one of the several enclosed silos, a batch of young brook trout is exposed to low doses of estradiol, a female sex hormone. While the females are unaffected by estradiol, the hormone causes the males in the group to essentially go through female puberty and produce eggs. The ovulating males are then bred with standard XY males, producing YY super males about 25% of the time.
The new super-male generation of trout--indistinguishable from XY males--go on to produce exclusively male fish when bred with any other brook trout. At the hatchery, the reproduction process is expedited by collecting milt and eggs on Tuesdays and fertilizing the eggs in large plastic bags.
Jared Riemenschneider scoops up two-year-old super-male brook trout in one of the Hayspur Fish Hatcherys enclosed silos on Tuesday, Oct. 19. Technicians place the broodstock in a large plastic bin--looking for fertility indicators like vibrant coloration--and toss back the fish that dont make the cut for breeding.
All standard XY males that hatch at Hayspur are chemically culled, while YYs are either kept as broodstock or released into the wild to breed with wild females and amplify the wild male population.
By age four, the YY brook trout weigh up to 2 pounds each and are culled due to size constraints. (In the wild, brook trout are rather short lived, averaging about three years.)
Currently, 3-inch fingerlings and 10-inch YY brook trout are released in the wild via helicopter, from high mountain lakes near Cape Horn Mountain north of Stanley to Spencer, according to Jared Riemenschneider, assistant manager of the hatchery.
All the indications that weve seen so far are very good, Anderson said. This is a first-in-the-world program.
See the original post here:
Fish and Game looks to improve alpine fisheries with 'super-male' brook trout - Idaho Mountain Express and Guide
- Rabbit Reproduction Basics - LafeberVet - June 25th, 2022
- Female orgasm | myVMC - June 25th, 2022
- 250,000 Year Old Insect Challenges Evolutionary Theory - The Epoch Times - June 25th, 2022
- Roe v Wade: men benefit from abortion rights too and should speak about them more - The Conversation - June 25th, 2022
- What is reproductive justice? Experts say it matters more than ever in a post-Roe world that is likely to disproportionately impact people of color -... - June 25th, 2022
- 'Sex in City Plants' reveals the secrets of urban reproduction - AIPT - June 25th, 2022
- 'Superwasp' Threatens America's Forests With Females Capable of Producing 1,000 Offspring - Newsweek - June 25th, 2022
- A CANADIAN SCIENTIST RECOGNIZED AS A L'ORAL-UNESCO FOR WOMEN IN SCIENCE INTERNATIONAL RISING TALENT 2022 - Yahoo Finance - June 25th, 2022
- Now That Roe v. Wade Has Been Overturned, Ratifying the ERA Is More Urgent Than Ever, Says Gloria Steinem - Oprah Mag - June 25th, 2022
- Increase in leptin levels in preeclampsia prompts cardiovascular cascade that puts mother and baby at risk - Jagwire Augusta - June 25th, 2022
- Abortion: Pro-Choice; Pro-Nothing; Pro-Life - Study the law with Blessed Mupatsi - Bulawayo24 News - June 25th, 2022
- All about the mites living and reproducing on your skin - Interesting Engineering - June 25th, 2022
- There's Convincing Evidence The Pill Can Cause Depression, And Some Types Are Worse Than Others - IFLScience - June 15th, 2022
- Evidence the pill causes depression - Cosmos - June 15th, 2022
- The Handmaid's Tale voted top book written by a woman for men to read - Cumnock Chronicle - June 15th, 2022
- 'Grease 2' turns 40: Why the 'more fun, female-forward' sequel is better than the original - USA TODAY - June 15th, 2022
- The Intriguing Life, Death, and Afterlife of an Indiana Mastodon - Atlas Obscura - June 15th, 2022
- New prehistoric plant discovery highlights the unexpected diversity of non-flowering plants - UM Today - June 15th, 2022
- Women Are Sharing How Little The Men In Their Lives Know About Reproduction - HuffPost - May 18th, 2022
- Review: 'Men' an arty horror film that stumbles in the woods - Star Tribune - May 18th, 2022
- The baffling truth about hammerhead worms in Ohio - WJW FOX 8 News Cleveland - May 18th, 2022
- PSHE KS2: Operation Ouch! How are babies made? Sperm, egg and reproductive organs - BBC - May 18th, 2022
- Opinion: Biological Science Rejects the Sex Binary, and Thats Good for Humanity - The Scientist - May 18th, 2022
- Opinion | Dont Be Fooled. Its All About Women and Sex. - The New York Times - May 18th, 2022
- Why abortion is deeply rooted in the history of humankind - EL PAS in English - May 18th, 2022
- ZooTampa Celebrates Rare Birth Of Litter Of Nearly Extinct Red Wolves - Patch - May 18th, 2022
- Abortion, Trans Health Care, and Right-Wing Pro-Natalism - The Intercept - May 18th, 2022
- Absent for More Than a Century, California Condors Soar Above the Redwoods Again - National Audubon Society - May 18th, 2022
- The Normalcy of White Male Violence - The Cut - May 18th, 2022
- Improving Women Economic Empowerment To Boost National Development - - The Tide - May 18th, 2022
- Is cannabis for womens pain as harmless as you think? Its time to look at the evidence - Geektime - April 22nd, 2022
- PINNACLE FERTILITY JOINS NATIONAL INFERTILITY AWARENESS WEEK TO RAISE AWARENESS AND EMPOWER THE INFERTILITY COMMUNITY - Yahoo Finance - April 22nd, 2022
- Minnesota bears may be fat and happy, rather than at risk - Star Tribune - April 22nd, 2022
- Diamond mines in the Northwest Territories are not a girls best friend - The Conversation - April 22nd, 2022
- Sacred hares, banished winter witches and pagan worship the roots of Easter Bunny traditions are ancient - Iowa Capital Dispatch - April 22nd, 2022
- RUDN University: Providing Young Generation With Excellent Professional Skills And Knowledge - Modern Diplomacy - April 22nd, 2022
- Higher risk of premenstrual disorders is seen with higher BMI in childhood - Contemporary Pediatrics - April 22nd, 2022
- Plastic pollution could make much of humanity infertile, experts fear - Salon - March 28th, 2022
- Reproductive and postsurgical outcomes of infertile women with deep infiltrating endometriosis - BMC Women's Health - BioMed Central - March 28th, 2022
- Decay of homologous chromosome pairs and discovery of males in the thelytokous fungus-growing ant Mycocepurus smithii | Scientific Reports -... - March 28th, 2022
- What is that noise in my woods? Explosion of amphibious reproduction underway in a vernal pool near you - News 5 Cleveland WEWS - March 28th, 2022
- Game Commission researchers find the oldest-recorded wild turkey in Pennsylvania history - WPMT FOX 43 - March 28th, 2022
- Endometriosis and Your Hormones: What's the Link? - Healthline - March 28th, 2022
- What is mitochondrial donation, and what do you need to know about it? - ABC News - March 28th, 2022
- Why gender perspectives must be included in the study of artificial intelligence - Equal Times - March 28th, 2022
- Innovent and Lilly Expand Strategic Partnership in Oncology - StreetInsider.com - March 28th, 2022
- A narwhal is still swimming with a pod of belugas in the St. Lawrence. Is this the year a narluga will be conceived? - The Globe and Mail - March 28th, 2022
- The people cloning their pets - BBC.com - March 28th, 2022
- Female dolphins have a clitoris much like humans - Science News Magazine - January 11th, 2022
- The significant role of post-pairing male behavior on the evolution of male preferences and female traits | Communications Biology - Nature.com - January 11th, 2022
- Revisiting social reproduction theory International Socialism - International Socialism Journal - January 11th, 2022
- Ireland's baby-making business: From egg freezing to IVF and everything in between - The Irish Times - January 11th, 2022
- Ridding Canadian medicine of conversion therapy - CMAJ - January 11th, 2022
- The metabolic cost of turning right side up in the Mediterranean spur-thighed tortoise (Testudo graeca) | Scientific Reports - Nature.com - January 11th, 2022
- Gender Bias In Futuristic Technologies: A Probe Into AI & Inclusive Solutions - Feminism in India - January 11th, 2022
- Malta among top performers in fertility treatment, but offers no education programme - Newsbook - January 11th, 2022
- 'Tinted With You' Is the Bite-Sized BL Web Drama We're Loving Right Now - Hornet - January 11th, 2022
- Wondrous and amazing: female California condors can reproduce without males - The Guardian - November 4th, 2021
- The egg freezing conundrum in Singapore not all social and ethical issues can be regulated by law - BioNews - November 4th, 2021
- Rosanna Davison: Im still waiting two years later to apply to be my daughters guardian - The Irish Times - November 4th, 2021
- Rosanna Davison reveals she's still waiting to apply to be her daughter's legal guardian - Goss.ie - November 4th, 2021
- This chemical could be stopping you from getting pregnant. What is it? - The Jerusalem Post - October 5th, 2021
- Protesters in Rock Island rally against anti-abortion laws - WQAD.com - October 5th, 2021
- Inside Female Dating Strategy, the Subreddit That Teaches Women to Level Up Against Scrotes and F*ckboys - Jezebel - October 5th, 2021
- Abortion testimonials from women in Congress punctuate hearing on SB8, the Texas bounty law - The Dallas Morning News - October 5th, 2021
- 2018 Camp Fire prompts 'true experiment of nature' - The Aggie - The Aggie - October 5th, 2021
- If it only depends on the brain, women can consume more alcohol than men The Clare People - The Clare People - October 5th, 2021
- To Fight Texass Abortion Law, These Houston Hospitality Veterans are Teaming Up - Eater Houston - October 5th, 2021
- Back-Seat Driver: The Parasite That Makes Bees Drop Off Its Babies - Entomology Today - October 5th, 2021
- Scientists Find A Species That Survived For Thousands of Years Without Having Sex - The Swaddle - October 5th, 2021
- October Weed of the Month: Red Hailstone - redlakenationnews.com - October 5th, 2021
- Barbie sent a doll on a zero-gravity flight to inspire young girls to work in space and STEM - Screen Shot - October 5th, 2021
- Amia Srinivasan What does Fluffy think? Pets with Benefits LRB 7 October 2021 - London Review of Books - October 5th, 2021
- New report sounds the alarm on global shortage of 900 000 midwives - World Health Organization - World Health Organization - May 10th, 2021
- Australian Treasurer to Address Women's Safety, Health in Budget - Bloomberg - May 10th, 2021
- A lot of shame: Why we need to talk about male infertility - TVO - May 10th, 2021
- Restricting abortion access fizzled in the 2021 Legislature; reproductive rights advocates expect future battles - Florida Phoenix - May 10th, 2021
- Op-Ed: How to change a health system that harms Black mothers - Los Angeles Times - May 10th, 2021
- COVID-19 Vaccination in Pregnant and Nursing Women: Expert Perspectives From Obstetrics and Epidemiology - Infectious Disease Advisor - May 10th, 2021
- Reproductive Rights Advocates Call for Biden to Curb Foreign Abortion Restrictions - Ms. Magazine - May 10th, 2021