#FishADay Brevoortia tyrannus Atlantic Menhaden. West Atlantic coasts and estuaries from Nova Scotia to Florida. Among its many colorful common names, my fave is "bughead" because they host parasitic isopods that replace their tongues (1/3) onlinelibrary.wiley.com/doi/10.1111/...
Infection prevalence and pathology of the cymothoid parasite <i>Olencira praegustator</i> in Atlantic menhaden
Isopod parasites in the family Cymothoidae can cause reduced growth, castration, or even mortality in their hosts. Olencira praegustator is a cymothoid that parasitizes the mouth and gill chamber of ...
onlinelibrary.wiley.com
October 6, 2026 at 7:52 AM
#FishADay Brevoortia tyrannus Atlantic Menhaden. West Atlantic coasts and estuaries from Nova Scotia to Florida. Among its many colorful common names, my fave is "bughead" because they host parasitic isopods that replace their tongues (1/3) onlinelibrary.wiley.com/doi/10.1111/...
#FishADay Gobiesox maeandricus Northern Clingfish. NE Pacific, shallow intercoastal waters. Pectoral and pelvic fins highly modified into very effective suction cup; holds Guinness World Record for "Stickiest Fish" with a cling force between 80 and 230 times its body weight. youtu.be/SySkRqjEb5w?...
This Fish Sucks: The Northern Clingfish
YouTube video by SciFri
youtu.be
September 29, 2026 at 8:15 AM
#FishADay Gobiesox maeandricus Northern Clingfish. NE Pacific, shallow intercoastal waters. Pectoral and pelvic fins highly modified into very effective suction cup; holds Guinness World Record for "Stickiest Fish" with a cling force between 80 and 230 times its body weight. youtu.be/SySkRqjEb5w?...
#FishADay Petromyzon marinus Sea Lamprey. Northern hemisphere anadromous; spawn in streams before maturing and going to sea (or lake--invasive species in the Great Lakes). Feed on blood of a variety of hosts, including sharks, which require tolerance to very high urea levels youtu.be/-KfoGaoH1XY?...
Basking sharks and Lampreys (Lampreys on SHARKS!)
YouTube video by BlueWorldTV
youtu.be
September 28, 2026 at 11:37 AM
#FishADay Petromyzon marinus Sea Lamprey. Northern hemisphere anadromous; spawn in streams before maturing and going to sea (or lake--invasive species in the Great Lakes). Feed on blood of a variety of hosts, including sharks, which require tolerance to very high urea levels youtu.be/-KfoGaoH1XY?...
#FishADay Scalicus engyceros An armored searobin with no English common name. Benthic, deep Pacfic, often associated with seamounts. Skitters along the seafloor on spidery "legs" that are actually modified pectoral fin rays.
www.eurekalert.org/multimedia/1...
www.eurekalert.org/multimedia/1...
Walking Behavior in Peristediid Fishes in the South China Sea
This video documents the distinctive benthic [deep-sea] behaviors of three peristediid (armored searobin) fishes observed in the South China Sea: Scalicus engyceros, Paraheminodus murrayi and Per...
www.eurekalert.org
September 21, 2026 at 3:59 PM
#FishADay Scalicus engyceros An armored searobin with no English common name. Benthic, deep Pacfic, often associated with seamounts. Skitters along the seafloor on spidery "legs" that are actually modified pectoral fin rays.
www.eurekalert.org/multimedia/1...
www.eurekalert.org/multimedia/1...
#FishADay Chirolophis decoratus Decorated Prickleback. Neritic--prefers hiding in shallow rocky habitats in N. Pacific from Kamchatka to Humboldt Bay. Elaborate cirri on head may help camouflage. Lays eggs in a mass which are guarded until hatch by males or females. youtu.be/5ZLJ2_Af0p4
Rare Footage of Decorated Warbonnet Guarding Eggs
YouTube video by ScubaMoto
youtu.be
September 18, 2026 at 8:31 AM
#FishADay Chirolophis decoratus Decorated Prickleback. Neritic--prefers hiding in shallow rocky habitats in N. Pacific from Kamchatka to Humboldt Bay. Elaborate cirri on head may help camouflage. Lays eggs in a mass which are guarded until hatch by males or females. youtu.be/5ZLJ2_Af0p4
#FishADay Sebastes melanops Black Rockfish. NE Pacific coast from Alaska to southern California. Croak, knock, and grunt by vibrating their swim bladders. One of a few species a recent study was able to identify just based on sound. Move over, birders! theconversation.com/scientists-h...
Scientists have identified unique sounds for 8 fish species
Researchers have known for centuries that some fish make sounds. Now, using special underwater acoustics, researchers have been able to identify sounds from eight different species.
theconversation.com
September 16, 2026 at 11:03 AM
#FishADay Sebastes melanops Black Rockfish. NE Pacific coast from Alaska to southern California. Croak, knock, and grunt by vibrating their swim bladders. One of a few species a recent study was able to identify just based on sound. Move over, birders! theconversation.com/scientists-h...
#FishADay Trachurus murphyi Chilean Jack Mackerel. Epipelagic South Pacific. One of the species being substituted in for NE Atlantic "true" mackerel, which has been declining. Of course, T. murphyi is also declining... www.ft.com/content/980a...
UK canned ‘mackerel’ now contains no mackerel
Critics say switch to tins comprising more sustainable species risks confusing consumers
www.ft.com
September 15, 2026 at 10:52 AM
#FishADay Trachurus murphyi Chilean Jack Mackerel. Epipelagic South Pacific. One of the species being substituted in for NE Atlantic "true" mackerel, which has been declining. Of course, T. murphyi is also declining... www.ft.com/content/980a...
#FishADay Retropinna tasmanica Tasmanian Smelt. Endemic to Tasmanian waters; breed in coastal estuaries and lowland streams, mature in open ocean. Also, like many other smelts and relatives, they smell like cucumber. That's about all that's known about them. link.springer.com/article/10.1...
Crying wolf, crying foul, or crying shame: alien salmonids and a biodiversity crisis in the southern cool-temperate galaxioid fishes? - Reviews in Fish Biology and Fisheries
The galaxioid fishes are the dominant, most speciose group of freshwater fishes (with >50 species) in the lands of the cool southern hemisphere, with representatives in western and eastern Australia, ...
link.springer.com
September 14, 2026 at 2:28 PM
#FishADay Retropinna tasmanica Tasmanian Smelt. Endemic to Tasmanian waters; breed in coastal estuaries and lowland streams, mature in open ocean. Also, like many other smelts and relatives, they smell like cucumber. That's about all that's known about them. link.springer.com/article/10.1...
#FishADay Helostoma temminckii Kissing Gourami. Native to still, FW in continental SE Asia and nearby islands, introduced more broadly across Asia, popular in pet trade. Some host parasitic algae, but of course most notable for mouth fighting behavior.
File:Helostoma temminkii kissing.ogv - Wikimedia Commons
commons.wikimedia.org
September 11, 2026 at 2:22 PM
#FishADay Helostoma temminckii Kissing Gourami. Native to still, FW in continental SE Asia and nearby islands, introduced more broadly across Asia, popular in pet trade. Some host parasitic algae, but of course most notable for mouth fighting behavior.
#FishADay Ameiurus nebulosus Brown Bullhead. FW Atlantic and Gulf Slope drainages of NA. First fish species documented to host a transmissible cancer--in this case, a melanoma that doesn't seem to be particularly deadly. www.nature.com/articles/d41...
Rare contagious cancer discovered in wild catfish
Transmissible tumours have been found in only a few types of animal, but there might be many more out there.
www.nature.com
September 10, 2026 at 2:28 PM
#FishADay Ameiurus nebulosus Brown Bullhead. FW Atlantic and Gulf Slope drainages of NA. First fish species documented to host a transmissible cancer--in this case, a melanoma that doesn't seem to be particularly deadly. www.nature.com/articles/d41...
#FishADay Solenostomus snuffleupagus Hairy Ghost Pipefish. Newly described from material collected in early 90s off Queensland. "Hair" actually skin filaments that help it blend in with reef macroalgae. Only ~3cm long--no wonder it went long undetected www.scientificamerican.com/article/a-re...
A real Mr. Snuffleupagus? Meet the ocean’s strangest new fish species
A strange, tiny fish that resembles the famous Sesame Street character camouflages amid red algae thanks to its flamboyant reddish “hairs”
www.scientificamerican.com
September 9, 2026 at 8:27 AM
#FishADay Solenostomus snuffleupagus Hairy Ghost Pipefish. Newly described from material collected in early 90s off Queensland. "Hair" actually skin filaments that help it blend in with reef macroalgae. Only ~3cm long--no wonder it went long undetected www.scientificamerican.com/article/a-re...
#FishADay Bassozetus robustus Robust Assfish. Deep sea down to 4000+m? Global? But might also be several species that should be split up. youtu.be/rktnlbkGUJc?...
Black Hole: Bassozetus
YouTube video by Caladan Oceanic
youtu.be
September 8, 2026 at 9:01 AM
#FishADay Bassozetus robustus Robust Assfish. Deep sea down to 4000+m? Global? But might also be several species that should be split up. youtu.be/rktnlbkGUJc?...
#FishADay Conger conger European Conger. Eastern Atlantic, rocky near-shore habitats. Maxing out at ~3m and ~72kg, world's heaviest eel. Migrate to deep water to spawn and die. youtu.be/9hLWgXoEXU4?...
CONGER EEL Monster of the Deep in UK Waters
YouTube video by Dave's Cave
youtu.be
September 7, 2026 at 7:27 AM
#FishADay Conger conger European Conger. Eastern Atlantic, rocky near-shore habitats. Maxing out at ~3m and ~72kg, world's heaviest eel. Migrate to deep water to spawn and die. youtu.be/9hLWgXoEXU4?...
#FishADay Demogorgonichthys arcanus Demon Cave Fish. One cave system in northern Alabama. Eyeless; appears to have lost its vision following an evolutionary pathway separate from a close blind relative that is found in the same system! www.scientificamerican.com/article/newl...
Newly discovered ‘demon cave fish’ hid out in Alabama military installation for 40 years
Scientists named this oddball creature after the Demogorgon from Stranger Things
www.scientificamerican.com
September 4, 2026 at 8:32 AM
#FishADay Demogorgonichthys arcanus Demon Cave Fish. One cave system in northern Alabama. Eyeless; appears to have lost its vision following an evolutionary pathway separate from a close blind relative that is found in the same system! www.scientificamerican.com/article/newl...
#FishADay Notropis percobromus Carmine Shiner. Eastern North America from Manitoba to Arkansas; mostly in river and stream pools w/ some current. Breeding males sport bright red heads. Overall IUCN least concern, but federally listed in Canada. www.dfo-mpo.gc.ca/about-notre-...
Aquatic Species at Risk, Carmine Shiner (Notropis percobromus)
Aquatic Species at Risk, Carmine Shiner (Notropis percobromus)
www.dfo-mpo.gc.ca
September 3, 2026 at 2:36 PM
#FishADay Notropis percobromus Carmine Shiner. Eastern North America from Manitoba to Arkansas; mostly in river and stream pools w/ some current. Breeding males sport bright red heads. Overall IUCN least concern, but federally listed in Canada. www.dfo-mpo.gc.ca/about-notre-...
#FishADay Cottus cognatus Slimy Sculpin. Nocturnal, cold streams and lakes from northeast Canada to eastern Siberia. Invasive Round Gobies may be muscling them out of their favorite nesting spots, as well as snarfing up eggs and young.
www.greatlakesnow.org/2023/06/19/i...
www.greatlakesnow.org/2023/06/19/i...
I Speak for the Fish: Searching for the elusive sculpin - Great Lakes Now
Sculpin are masters of camouflage and only the most discerning of observers will ever spot one.
www.greatlakesnow.org
August 31, 2026 at 12:14 PM
#FishADay Cottus cognatus Slimy Sculpin. Nocturnal, cold streams and lakes from northeast Canada to eastern Siberia. Invasive Round Gobies may be muscling them out of their favorite nesting spots, as well as snarfing up eggs and young.
www.greatlakesnow.org/2023/06/19/i...
www.greatlakesnow.org/2023/06/19/i...
I know #FishADay hasn't exactly been every day lately and it's not actually a fish, but while diving on vacation in Lanyu this week we saw a cuttlefish and I can't stop thinking about it,
April 15, 2026 at 7:00 AM
I know #FishADay hasn't exactly been every day lately and it's not actually a fish, but while diving on vacation in Lanyu this week we saw a cuttlefish and I can't stop thinking about it,
#FishADay Albatrossia pectoralis Giant Grenadier. Deep (usually 400 to 1,000 m) benthic North Pacific, up to 2m long. Juveniles seem to be pelagic, settling to the bottom as they mature. Glorious video by NOAA Ocean Exploration youtu.be/yuLDm3mXvas
Now That's Deep...And CLOSE!
YouTube video by oceanexplorergov
youtu.be
March 6, 2026 at 2:02 PM
#FishADay Albatrossia pectoralis Giant Grenadier. Deep (usually 400 to 1,000 m) benthic North Pacific, up to 2m long. Juveniles seem to be pelagic, settling to the bottom as they mature. Glorious video by NOAA Ocean Exploration youtu.be/yuLDm3mXvas
#FishADay Parupeneus barberinus Dotdash goatfish. Indo-Pacific reef flats and lagoons down to 100m. Names for caudal peduncle dot and prominent stripe; stripe is black in shallower fishes, red in deeper ones. Enjoy some classic barbel snuffling through sand for tasty morsels.
youtu.be/YxK9lrHQbYw
youtu.be/YxK9lrHQbYw
Dash Dot Goatfish and the Barbels
YouTube video by Ismail Nadheem
youtu.be
February 5, 2026 at 10:14 AM
#FishADay Parupeneus barberinus Dotdash goatfish. Indo-Pacific reef flats and lagoons down to 100m. Names for caudal peduncle dot and prominent stripe; stripe is black in shallower fishes, red in deeper ones. Enjoy some classic barbel snuffling through sand for tasty morsels.
youtu.be/YxK9lrHQbYw
youtu.be/YxK9lrHQbYw
#FishADay Eleotris sandwicensis O'opu 'akupa aka Sandwich Island Sleeper. Hawai'i's only endemic sleeper goby. Hatch in lower streams, move down to marine waters to mature, then return to freshwater. Increasingly frequent droughts on the islands could be a problem. www.nps.gov/articles/pac...
Stream Life in Hawai‘i National Parks (U.S. National Park Service)
How changes in weather patterns effect animal life in streams monitored by PACN I&M
www.nps.gov
February 2, 2026 at 2:00 PM
#FishADay Eleotris sandwicensis O'opu 'akupa aka Sandwich Island Sleeper. Hawai'i's only endemic sleeper goby. Hatch in lower streams, move down to marine waters to mature, then return to freshwater. Increasingly frequent droughts on the islands could be a problem. www.nps.gov/articles/pac...
#FishADay Enneacanthus chaetodon Blackbanded Sunfish. Thrives in tannic, vegetated waters from New Jersey to Florida. Range decreasing and fragmenting with drying of wetlands; extirpated or endangered in some parts of Eastern US. Pet trade also a problem in some places. www.fws.gov/rivers/story...
Bringing blackbanded sunfish back to blackwater habitat in Maryland | U.S. Fish & Wildlife Service
On a picture-perfect, mid-September Monday, a dozen staff from the Maryland Department of Natural Resources and the U.S. Fish and Wildlife Service caravaned down a rutted dirt road in a Wildlife Manag...
www.fws.gov
January 30, 2026 at 1:19 PM
#FishADay Enneacanthus chaetodon Blackbanded Sunfish. Thrives in tannic, vegetated waters from New Jersey to Florida. Range decreasing and fragmenting with drying of wetlands; extirpated or endangered in some parts of Eastern US. Pet trade also a problem in some places. www.fws.gov/rivers/story...
#FishADay Icichthys lockingtoni Medusafish. N. Pacific Ocean, pelagic. Young seen offshore sheltering in jellyfish (time code 0:29 in this video from @mbarinews.bsky.social, although really, you should watch the whole thing; there are juvy king crabs riding a sea pig).
youtu.be/VhG7LNUcvYc
youtu.be/VhG7LNUcvYc
The Hitchhiker’s Guide to the Deep Sea: Friend, foe, or frenemy?
YouTube video by MBARI (Monterey Bay Aquarium Research Institute)
youtu.be
January 29, 2026 at 2:04 PM
#FishADay Icichthys lockingtoni Medusafish. N. Pacific Ocean, pelagic. Young seen offshore sheltering in jellyfish (time code 0:29 in this video from @mbarinews.bsky.social, although really, you should watch the whole thing; there are juvy king crabs riding a sea pig).
youtu.be/VhG7LNUcvYc
youtu.be/VhG7LNUcvYc
#FishADay Mitsukurina owstoni Goblin Shark. Benthopelagic, mostly near continental slopes and seamounts. Known from < 250 captured individuals, so a recent well-documented recreational rod-and-reel capture (and release!) off the Canaries is very exciting.
oceanographicmagazine.com/news/rare-de...
oceanographicmagazine.com/news/rare-de...
Rare deep-sea shark seen for first time in Canary Island waters
First-of-its kind sighting expands knowledge about elusive sharks , and underlines importance of the Canary Islands’ deep water habitats
oceanographicmagazine.com
January 28, 2026 at 9:35 AM
#FishADay Mitsukurina owstoni Goblin Shark. Benthopelagic, mostly near continental slopes and seamounts. Known from < 250 captured individuals, so a recent well-documented recreational rod-and-reel capture (and release!) off the Canaries is very exciting.
oceanographicmagazine.com/news/rare-de...
oceanographicmagazine.com/news/rare-de...
#FishADay Neocyttus helgae False Boarfish. North Atlantic below 900m. 2009 submersible study documented territorial displays, including raising dorsal fin spine and trying to bite the vehicle. www.youtube.com/watch?v=MhD3...
Oreo (aka, False Boarfish): Voyage to the Ridge 2022
YouTube video by oceanexplorergov
www.youtube.com
January 26, 2026 at 9:02 AM
#FishADay Neocyttus helgae False Boarfish. North Atlantic below 900m. 2009 submersible study documented territorial displays, including raising dorsal fin spine and trying to bite the vehicle. www.youtube.com/watch?v=MhD3...
#FishADay Sphyraena barracuda Great Barracuda. Global tropical and warm temperate oceans. Ambush prey in open water, swimming them down at up to 58 km/h (36 mph). Attacks on humans do happen (read on), but ciguatera seems to be biggest barracuda-associated danger.
www.youtube.com/watch?v=dOsA...
www.youtube.com/watch?v=dOsA...
Great barracuda (Sphyraena barracuda) in 4K
YouTube video by Red Sea Bit
www.youtube.com
January 23, 2026 at 2:42 PM
#FishADay Sphyraena barracuda Great Barracuda. Global tropical and warm temperate oceans. Ambush prey in open water, swimming them down at up to 58 km/h (36 mph). Attacks on humans do happen (read on), but ciguatera seems to be biggest barracuda-associated danger.
www.youtube.com/watch?v=dOsA...
www.youtube.com/watch?v=dOsA...