How do you know if fish is spoiled?
The best way to determine if fish has gone bad is to smell it. If the fish smells sour or spoiled, throw it out. If the fish has a mild ocean smell, it's likely safe to eat—but if you aren't certain, there are other signs you can look for. For example, it's bad fish if it appears or feels slimy and/or has a dull color.
When fish starts going bad—at the store or in your fridge—you will notice the color, texture and smell start to change. The fish scent will become stronger, which is a sign of the proteins breaking down. It may also feel slimy and develop a grayish tint.
Inspect the raw fish for a milky color.
Fish meat is typically light pink or white in color, with a thin, clear film of liquid. As fresh or refrigerated fish ages and begins to go bad, the meat will take on a glossy, milky color. The milky parts of the fish may also take on a blue- or gray-ish tint.
In old fish they are dry, covered with sticky slime, grayish-brown in color and smell bad.
Fish spoil quickly because they are creatures of the water and therefore of the cold. Deep ocean water is only a few degrees above freezing, and surface waters seldom exceed 70 degrees. The microbes and body enzymes of cattle, pigs and chickens are accustomed to operating above 90 degrees.
Raw fish and shellfish should be kept in the refrigerator (40 °F/4.4 °C or less) only 1 or 2 days before cooking or freezing. After cooking, store seafood in the refrigerator 3 to 4 days. Any frozen fish or shellfish will be safe indefinitely; however, the flavor and texture will lessen after lengthy storage.
In terms of smell, spoiled fish will generally have a fishy, sour, or ammonia-like stench. Appearance-wise, spoiled fish may appear to be dry or mushy in certain areas, and the gills may have slime. Spoiled fish will also have flesh that is soft, or does not spring back when pressed upon.
...
1.1. 2 Characteristics of fresh and spoiled fish and shellfish.
FRESH FISH | SPOILED FISH | |
---|---|---|
MUSCLE TISSUE | White | Pinkish, especially around backbone |
VENT | Pink, not protruding | Brown, protruding |
ODOR | Fresh, fishy odor | Stale, sour or putrid |
COLOR | Bright | Faded |
Conclusion: Fish spoilage results from three basic mechanisms: Enzymatic autolysis, oxidation, microbial growth. Low temperature storage and chemical techniques for controlling water activity, enzymatic, oxidative and microbial spoilage are the most common in the industry today.
Spoilage By Bacteria
Bacteria are the most important cause of seafood spoilage. Millions of bacteria are present in the surface slime, on the gills, and in the gut of living seafood species.
What are the signs of food spoilage?
Signs of food spoilage may include an appearance different from the food in its fresh form, such as a change in color, a change in texture, an unpleasant odor, or an undesirable taste.
Leftover fish should be safe for you to eat for an absolute maximum of up to 3 days after it has been cooked, according to the USDA.

Never leave seafood or other perishable food out of the refrigerator for more than 2 hours or for more than 1 hour when temperatures are above 90°F. Bacteria that can cause illness grow quickly at warm temperatures (between 40°F and 140°F).
Fresh fish should taste and smell that way: fresh, briny and sweet, not musty, yeasty, bitter or fishy. The texture should be resilient, firm and smooth. Older fish that has become mealy or mushy tastes bad and smells worse.
Be it raw or cooked, fish and other seafood can safely sit out for up to two hours when left at room temperature. But when the temperature reaches 90 degrees Fahrenheit or higher, the time seafood can stay out reduces to one hour as bacteria grow rapidly at this rate.
If food is allowed to remain at room temperature for two hours or longer, bacteria can multiply and cause food poisoning. - Even a tiny amount of contaminated food can cause severe illness. If you have any doubt about the safety of the food, throw it out!"
Signs That Frozen Seafood Has Gone Bad
Once your fish has thawed, check for any strong "fishy" odors, which are a sign that it's past its peak. Seaver says to look for ice crystals and dry or discolored spots, all of which indicate that the fish was exposed to air and thawed briefly before re-freezing.
Look for firm, shiny flesh: The flesh of the fish should bounce back on touching it. The skin has a natural metallic glow and should not look dull. The surface of the skin must be tight and the scales might be tightly attached. Cracked skin or loose scales could be signs of rotting fish.
Thorough cleaning of the body cavity and chilling of the fish will prevent spoilage. Fish spoilage occurs rapidly at summer temperatures; spoilage is slowed down as freezing temperatures are approached.
The normal spoilage will be calculated as the total number of spoiled units, divided by the total units produced, and multiplied by 100. In this case, it would be 500 / 10,000 x 100 = 5%.
What are the 3 types of spoilage?
- 1 Microbial spoilage. Microbial spoilage is caused by microorganisms like fungi (moulds, yeasts) and bacteria. ...
- 2 Physical spoilage. Physical spoilage is due to physical damage to food during harvesting, processing or distribution. ...
- 3 Chemical spoilage. ...
- 4 Appearance of spoiled food.
- They don't play well with others. ...
- They drive people away. ...
- They have frequent tantrums. ...
- They're not helpful. ...
- They don't say “thank you.” ...
- They start sentences with “I need.” ...
- They're not generous. ...
- They talk to you like a peer.
Symptoms occur rapidly, usually within an hour of eating spoiled fish, and typically include flushing, itching, rash, headache, rapid or irregular heartbeat, dizziness, sweating, burning of the mouth and throat, diarrhea, nausea, vomiting, and abdominal cramps.
“If you cook it thoroughly enough any flora of microbes you have there will be knocked out.” “I would go so far as to say that even rotten fish can be eaten without the consumer getting sick, as long as the fish is given sufficienty heat treatment,” says Østli.
There are two types of food poisoning you can get from eating fish. They are ciguatera poisoning and scombroid poisoning. Ciguatera poisoning symptoms include abdominal cramps, nausea, vomiting, and diarrhea. Symptoms can progress to headache, muscle aches, and itchy, tingly, or numbness of the skin.
Scombroid food poisoning, also known as simply scombroid, is a foodborne illness that typically results from eating spoiled fish. Symptoms may include flushed skin, headache, itchiness, blurred vision, abdominal cramps, and diarrhea.
Leftover fish should be safe for you to eat for an absolute maximum of up to 3 days after it has been cooked, according to the USDA.
Information. Cooked fish and other seafood can be safely stored in the refrigerator 3 to 4 days. Refrigeration slows but does not prevent bacterial growth. Therefore, it's important to use food within recommended time before it spoils or becomes dangerous.
After the use-by date, don't eat, cook or freeze your food.
Pufferfish (some species are also called toadfish) have been given the title 'Most Poisonous Fish' and have also been labeled the second most poisonous vertebrate in the world. The toxin responsible for ranking this fish so high in the “danger zone” is called tetrodotoxin.
What fish are not edible?
Are you aware that four fish have been designated by the U.S. Food and Drug Administration ( USDA ) and Environmental Protection Agency ( EPA ) to be unsafe to eat due to their typically high levels of mercury? Making the “do not eat” list are King Mackerel, Shark, Swordfish and Tilefish.
Whilst the spoilage of fresh and highly salted fish is well understood, much less is known about spoilage of lightly preserved fish products. It is concluded that the spoilage is probably caused by lactic acid bacteria, certain psychotrophic Enterobacteriaceae and/or Photobacterium phosphoreum.
References
- https://aquaticsunlimited.com/treating-saltwater-ich/
- https://hakaimagazine.com/features/fish-feel-pain-now-what/
- https://www.letsenvision.com/blog/blindness-and-animals
- https://www.lindavision.com/2022/07/11/what-causes-cloudy-vision-in-one-eye/
- https://www.health.ny.gov/publications/0911/
- https://cafishvet.com/fish-health-disease/fish-popeye/
- https://www.wefixeyes.co.nz/articles/why-most-humans-cant-see-clearly-underwater/
- https://blog.aquariuminfo.org/curing-ich-best-3-ways-remove-aquarium-ich/
- https://www.yihufish.com/fishkeeping-articles/freshwater/why-is-my-aquarium-water-cloudy/
- https://www.allaboutvision.com/eye-care/eye-health/fish-oil-benefits/
- https://myfwc.com/research/saltwater/fish/snook/reduce-catch-release-mortality/
- https://famfocuseye.com/5-early-signs-of-glaucoma/
- https://www.healthline.com/health/eye-health/how-to-cure-blurry-vision-naturally
- https://www.epropulsion.com/post/does-noise-scare-fish-away/
- https://anglingunlimited.com/fishing/catch-release-properly/
- https://www.umkelloggeye.org/conditions-treatments/glaucoma
- https://www.lakehomes.com/info/articles-and-news/the-science-behind-clear-and-murky-lakes
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8348690/
- https://www.mountsinai.org/health-library/symptoms/cloudy-cornea
- https://fishlab.com/freshwater-ich/
- https://www.medicalnewstoday.com/articles/fish-oil-for-dry-eyes
- https://www.tasteofhome.com/collection/how-to-tell-if-fish-is-fresh/
- https://moffitt.org/cancers/brain-tumor/symptoms/eye-problems/
- http://elearning.servsafe.com/content/ssmct6/assets/en/pdf/receiving_criteria.pdf
- https://ask.usda.gov/s/article/Is-it-safe-to-use-food-from-dented-cans
- https://newschannel9.com/sports/outdoors/what-fish-see-and-what-they-dont
- https://a-abel.com/cloudy-water/
- https://faunalytics.org/fishes-remember-being-caught-for-a-long-time/
- https://outdoors.stackexchange.com/questions/4982/is-it-really-necessary-to-gut-a-fish
- https://www.hartz.com/changing-the-water-cleaning-the-tank/
- https://fishmongerapproved.com/7-things-to-avoid-when-filleting-fish/
- https://www.britannica.com/science/ich
- https://www.sms-magic.com/docs/salesforce/faq/7-what-does-rejected-delivery-status-mean/
- https://www.fda.gov/food/buy-store-serve-safe-food/selecting-and-serving-fresh-and-frozen-seafood-safely
- https://wilmartheye.com/blog/what-does-vision-with-glaucoma-look-like
- https://www.fishfrombeach.com/clean-a-fish-after-catching-it/
- https://www.lawinsider.com/dictionary/rejected-order
- https://be.chewy.com/fish-vision-is-better-than-you-think/
- https://land-based-fishing.com/how-to-gut-and-clean-a-fish-in-5-easy-steps/
- https://www.fishtankworld.com/salt-in-freshwater-tanks/
- https://oceanservice.noaa.gov/facts/fish-sleep.html
- https://www.latimes.com/archives/la-xpm-1989-03-30-fo-565-story.html
- https://nptelegraph.com/sports/outdoors/rick_windham/so-what-do-fish-actually-see-from-their-world/article_87030fff-703f-52d5-a766-43b645fb0f47.html
- https://www.hopkinsmedicine.org/health/conditions-and-diseases/glaucoma
- https://www.newvisionclinics.com.au/wp-content/uploads/2014/10/9-cornealhazech6small.pdf
- https://www.swimuniversity.com/cloudy-pool-water/
- https://www.plymouthfamilyoptometry.com/2022/01/12/can-dehydration-affect-your-eyes/
- https://www.ntlabs.co.uk/knowledge-hub/medicinal-treatment-rules/
- https://www.optometrists.org/general-practice-optometry/guide-to-eye-health/11-causes-of-blurry-vision-in-one-eye/
- https://www.webmd.com/eye-health/cornea-conditions-symptoms-treatments
- https://ask.usda.gov/s/article/How-long-can-you-store-fish
- https://practicequiz.com/q/under-which-listed-condition-should-you-reject-t
- https://www.thesprucepets.com/cloudy-aquarium-water-1378803
- https://www.greatbritishchefs.com/how-to-cook/how-to-gut-a-fish
- https://creature-companions.in/why-fish-die-after-a-water-change-and-how-to-prevent-it/
- http://www.aquariumadventure.com/AquariumAdventureTipSheet2.htm
- https://www.seriouseats.com/best-way-to-store-fish-refrigerator-ice-packs
- https://kb.rspca.org.au/knowledge-base/what-is-the-most-humane-way-to-euthanase-aquarium-fish/
- https://www.northwoodspets.com/ich-information-and-treatment/
- https://fairviewadc.com/tbi/blurry-vision-causes/
- https://uwm.edu/news/examining-regeneration-through-a-fishs-eye/
- https://www.sciencedaily.com/releases/2003/02/030210075908.htm
- https://www.cnn.com/2016/06/07/health/fish-human-face-recognition-study-trnd/index.html
- https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=45491c6b2244591d2fbbcd50397bc6e2&term_occur=999&term_src=Title:48:Chapter:8:Subchapter:G:Part:846:Subpart:846.3:846.370-1
- https://www.felp.ac.uk/content/rejection-goods-or-services
- https://possector.com/menu/how-to-tell-if-fish-is-fresh
- https://www.mrsaltwatertank.com/terrible-advice-tuesdays-ich-is-in-the-water/
- https://www.bobvila.com/articles/cloudy-water/
- https://www.eatingwell.com/article/7959141/how-to-refuse-food-politely-according-to-an-expert/
- https://en.wikipedia.org/wiki/Vision_in_fish
- https://www.hartz.com/stress-in-fish-symptoms-and-solutions/
- https://www.optometrists.org/general-practice-optometry/guide-to-eye-conditions/guide-to-blurry-vision-and-headaches/treatments-for-stress-related-vision-problems/
- https://advancedaquariumconcepts.com/how-to-treat-ich/
- https://www.takemefishing.org/how-to-fish/how-to-catch-fish/how-to-store-fish/
- https://www.visioncareofmaine.com/2021/09/30/is-blurry-vision-dry-eye-syndrome/
- https://www.geisinger.org/health-and-wellness/wellness-articles/2017/06/01/20/44/everythings-fuzzy-four-common-causes-of-blurry-vision
- https://www.rd.com/list/foods-to-never-wash-before-cooking/
- https://www.goodhousekeeping.com/uk/a660058/can-a-retailer-refuse-to-give-me-a-refund/
- https://www.cancercenter.com/treatment-options/precision-medicine/genetic-testing/fish-test
- https://www.ncascade.com/what-causes-your-vision-to-fluctuate/
- https://www.bettacarefishguide.com/blind-betta-fish/
- https://global-poolproducts.com/causes-of-a-cloudy-salt-water-pool/
- https://www.sciencefocus.com/nature/can-fish-see-in-the-dark/
- https://lookafteryoureyes.org/eye-conditions/glaucoma/
- https://www.eyemichigan.com/why-is-my-vision-blurry-sometimes/
- https://www.courierpoint.com/guides/info/refused-delivery
- https://www.clearwatersystems.com/common-water-problems/cloudy-drinking-water-problem/
- https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/eating-with-diabetes/food-psychology/food-family-and-diabetes-how-to-say-no-politely
- https://edis.ifas.ufl.edu/publication/FA006
- https://www.rd.com/article/how-long-keep-fish-in-fridge/
- https://www.realtree.com/brow-tines-and-backstrap/it-s-hot-you-shot-a-deer-now-what
- https://versanthealth.com/blog/top-8-ways-to-improve-vision-over-50/
- https://seachem.zendesk.com/hc/en-us/articles/360022396953-FAQ-Do-I-need-to-turn-the-filter-off-when-using-a-Seachem-medication-
- https://happilyeverafteretc.com/how-to-treat-ick-on-your-fish/
- https://www.mayoclinic.org/diseases-conditions/glaucoma/symptoms-causes/syc-20372839
- https://www.lovetoknowpets.com/aquariums/do-betta-fish-recognize-interact-their-owners
- https://www.quora.com/I-bought-some-frozen-fish-and-it-wasnt-gutted-Should-I-eat-it
- https://www.fdacs.gov/Consumer-Resources/Recreation-and-Leisure/Aquarium-Fish/Aquarium-Water-Quality-Sources-of-Water
- https://quizlet.com/50075924/chapters-6-and-7-flash-cards/
- https://www.360training.com/blog/when-accept-refuse-seafood-poultry-meat-shipment
- https://www.aquariumcoop.com/blogs/aquarium/aquarium-salt-for-sick-fish
- https://www.cdc.gov/healthypets/pets/fish.html
- https://www.pond-planet.co.uk/blog/how-to-get-crystal-clear-aquarium-water/
- https://www.fao.org/3/w0495e/w0495E03.htm
- https://aquaproshq.com/blogs/aquarium-guides/crystal-clear-aquarium-water
- https://www.90210eyes.com/blog/omega-3-for-eye-health/
- https://www.tetra-fish.com/ask-tetra/faqs/aquarium/aquarium-water-problems/my-water-is-cloudy-how-can-i-clear-the-water.aspx
- https://wtamu.edu/~cbaird/sq/2020/02/11/do-blind-people-dream-in-visual-images/
- https://mayfieldclinic.com/pe-ich.htm
- https://www.grantregional.com/health-and-wellness/posts/glaucoma-the-thief-of-sight/
- https://aquariumswest.com/blogs/helpful-articles/how-to-treat-ich
- https://www.gellervision.com/pages/glaucoma.html
- https://housedpet.com/can-you-add-fish-to-a-cloudy-tank/
- https://www.mcgill.ca/oss/article/you-asked/do-fish-drink
- https://www.truenorthseafood.com/seafood-school/cooking/other-cooking-tips/
- https://fishlab.com/water-clarifier/
- https://www.nature.com/articles/1401014a0
- https://www.healthonemedicine.com/blog/5-early-warning-signs-of-glaucoma-that-shouldnt-be-ignored
- https://www.onemedical.com/blog/eat-well/healthy-fish-eating-guide/
- https://www.sarahremmer.com/the-extreme-picky-eater-when-a-parent-should-worry/
- https://www.tfhmagazine.com/articles/freshwater/preventing-ich-full-article
- https://theconversation.com/curious-kids-how-do-fish-sleep-126018
- https://thenjeye.com/stop-glaucoma-progression/
- https://be.chewy.com/popeye-disease-in-fish/
- https://www.aquariumcoop.com/blogs/aquarium/how-to-treat-ich-on-freshwater-fish
- https://www.servsafe.com/ServSafe/media/ServSafe/Documents/2013_Mgr-Comprehensive-PPT-chapters-4-to-6.pptx
- https://www.petland.ca/pages/new-tank-syndrome
- https://nofima.com/worth-knowing/bleeding-and-residual-blood-in-fish/
- https://denverzoo.org/animals/blind-cave-fish/
- https://badmanstropicalfish.com/blind-betta-fish/
- https://extension.psu.edu/proper-care-and-handling-of-fish-from-stream-to-table
- https://www.aquasabi.com/aquascaping-wiki_algae_bacterial-bloom
- https://www.thesprucepets.com/treat-ichthyophthirius-multifiliis-1378482
- https://tankaddict.com/ich/
- https://blog.petloverscentre.com/why-is-my-fish-tank-cloudy/
- https://felixgray.com/pages/blurred-vision
- https://idfg.idaho.gov/question/what-be-done-badly-injured-fish-not-legal-keepi-often-catch-smallmouth-bass-are-too-small
- https://www.urban-optics.com/blog/how-to-fix-blurry-vision.html
- https://guidesly.com/fishing/blog/fish-on-ice-how-long-can-you-keep-them-ungutted
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5223567/
- https://www.science.org/content/article/cave-fish-go-blind-purpose
- https://www.bhg.com/recipes/fish/basics/how-to-tell-if-fish-is-fresh/
- https://aquariumscience.org/index.php/10-2-2-6-filtration-of-ich/
- https://www.merriam-webster.com/thesaurus/reject
- https://www.thesprucepets.com/understanding-freshwater-aquarium-lighting-4082719
- https://www.dogbreedinfo.com/fishhealthdiseases/ichfish.htm
- https://www.eurosender.com/blog/en/receiver-refused-delivery/
- https://fishroom.co.uk/2019/12/09/bacterial-bloom-cloudy-water-ammonia-nitrite-spike-what-do-i-do/
- https://sentientmedia.org/do-fish-feel-pain/
- https://www.quora.com/Is-it-rude-to-reject-the-food-when-invited-over-someone-s-home
- https://www.aquariumcarebasics.com/aquarium-water-quality/cloudy-aquarium-water/
- https://www.fooddocs.com/post/when-should-you-refuse-to-accept-food-in-a-shipment
- https://www.eyeclinicpdx.com/blog/cataracts/clearing-your-cloudy-vision/
- https://www.healthline.com/health/food-nutrition/how-to-stop-eating-junk-food
- https://www.homedepot.com/c/ah/how-to-clear-a-cloudy-pool/9ba683603be9fa5395fab90edd34116
- https://my.clevelandclinic.org/health/diseases/22948-food-aversion
- https://www.letsenvision.com/blog/5-facts-about-blind-people-and-blindness
- https://www.healthline.com/health/how-to-improve-eyesight
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3258567/
- https://byjus.com/question-answer/do-fishes-cry/
- https://en.wikipedia.org/wiki/Ichthyophthirius_multifiliis
- https://www.mrsaltwatertank.com/terrible-advice-tuesdays-t-a-tues-when-your-fish-is-new-dont-feed-it/
- https://www.ncesc.com/how-to-refuse-a-package-usps/
- https://thehumaneleague.org/article/do-fish-feel-pain
- https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-anxiety-and-eating-issues-in-children/
- https://www.healthline.com/health/cloudy-vision
- https://www.livescience.com/44571-blind-cavefish-use-mouth-suction.html
- https://www.themeateater.com/fish/general/what-colors-do-fish-actually-see
- https://coopervision.com/eye-health-and-vision/improving-eyesight-naturally
- https://vanislemarina.com/cleaning-fish-on-a-boat/
- https://aquariumscience.org/index.php/10-2-4-epistylis/
- https://www.lbc.co.uk/radio/special-shows/the-mystery-hour/human-body/do-eyeballs-grow-with-age-27112/
- https://guide.michelin.com/en/article/dining-in/%E5%A6%82%E4%BD%95%E6%8C%91%E9%81%B8%E6%9C%80%E4%BD%B3%E9%AE%AE%E9%AD%9A
- https://quizlet.com/163001853/chapter-5-flow-of-food-purchasing-receiving-and-storage-flash-cards/
- https://montereybay.noaa.gov/research/techreports/trkochevar1998.html
- https://modestfish.com/cloudy-fish-tank/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5307940/
- https://fisheries.tamu.edu/files/2013/09/Ichthyophthirius-multifiliis-White-Spot-Infections-in-Fish.pdf
- https://www.sciencefocus.com/nature/do-fish-ever-get-bored-in-fish-tanks/
- https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/safe-temperature-chart
- https://www.medicalnewstoday.com/articles/blurry-vision-in-one-eye
- https://www.thelifeyoucansave.org/blog/the-gift-of-sight-what-you-can-do-to-reverse-blindness/
- https://fishyourassoff.com/scents-that-attract-and-repel-fish.html
- https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2790105
- https://www.gfs.com/en-us/ideas/food-service-delivery-guidelines-when-reject-items
- https://www.verywellhealth.com/corneal-haze-3422130
- https://www.petplace.com/article/fish/general/common-eye-problems-of-pet-fish/
- https://hikingandfishing.com/catch-and-release-fishing/
- https://www.webmd.com/food-recipes/ss/slideshow-picky-eating
- https://dwazoo.com/animal/blind-cavefish/
- https://www.encyclopedia.com/food/encyclopedias-almanacs-transcripts-and-maps/acceptance-and-rejection
- https://coopervision.com/blog/why-vision-blurry-after-looking-screen-too-long
- https://cafishvet.com/fish-health-disease/fish-cloudy-eyes/
- https://be.chewy.com/getting-rid-of-ich-on-fish-and-aquariums/
- https://global.essilor.com/ie/blog/what-affects-the-eyes/why-do-you-have-cloudy-vision
- https://quizlet.com/107686253/servsafe-chapter-5-flash-cards/
- https://aquaculture.ca.uky.edu/sites/aquaculture.ca.uky.edu/files/srac_476_ich_white_spot_disease.pdf
- https://www.icarevision.com/service/corneal-repair/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC314054/
- https://www.peta.org/about-peta/why-peta/catch-and-release-fishing/
- https://www.verywellhealth.com/cloudy-vision-in-one-eye-5101196
- https://www.theguardian.com/news/2018/oct/30/are-we-wrong-to-assume-fish-cant-feel-pain
- https://www.thespruceeats.com/gut-and-scale-a-fish-1300845
- https://www.offthescaleangling.ie/the-science-bit/fish-vision/
- https://www.telegraph.co.uk/news/earth/wildlife/7749118/Fish-are-scared-of-their-own-reflections.html
- https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma
- https://hign.org/consultgeri/resources/symptoms/refusing-eat-drink
- https://food.ndtv.com/food-drinks/how-to-tell-if-your-fish-is-fresh-5-tips-to-remember-1751503
- https://lifehacker.com/how-to-politely-get-out-of-eating-food-you-dont-like-1820668287
- https://www.csmonitor.com/Science/2015/1119/How-fish-can-turn-invisible-in-the-open-sea
- https://neoretina.com/blog/faqs/how-long-does-it-take-to-become-blind-from-glaucoma/
- https://quizlet.com/502290688/servsafe-chapter-5-purchasing-receiving-and-storing-flash-cards/
- https://www.swelluk.com/help-guides/how-to-do-a-water-change-without-killing-fish/
- https://aquariumgenius.com/do-aquarium-fish-need-light-at-night-or-can-you-turn-it-off/
- https://www.thehealthyjournal.com/faq/what-must-be-rejected-in-a-delivery
- https://www.bulkreefsupply.com/content/post/md-2021-02-marine-ich-life-cycle-diagram-cryptocaryon-irritans-treatment
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038323/
- https://www.coastaleyecare.net/cataracts-eval/
- https://quizlet.com/569907290/criteria-for-specimen-rejection-flash-cards/
- https://www.theguardian.com/lifeandstyle/2013/jul/21/how-to-fillet-a-fish