FishWiki

Tonight, we'll look at angler fish!

If you’re being hunted by the female anglerfish, the last thing you’ll ever see is a flashing blue-green light. Above its gaping mouth and gnashing teeth, the fish sports a glowing lure dangling from a rod on its forehead.

The source of light coming from this bulbous appendage is bioluminescent bacteria. Although these provide bright flashes that entice prey to come near, they can’t illuminate on their own. In order to glow, the bacteria need some sort of cue from the anglerfish—suggesting a symbiotic relationship between the fish and microbes.

Once prey is within chomping distance, the female fish’s flexible bone structure and expandable stomach make it possible to swallow animals twice its size. In a part of the ocean that’s low on fresh food, it’s a good idea to stock up when you can.

Measuring only about a tenth of a females’ size, diminutive male anglerfish don’t have a fierce reputation. They lack a glowing esca, but are more muscular than females, letting them swim long distances to find a mate.

When anglerfish find the right match, they’re not afraid of commitment—with a single, fateful love bite, males permanently attach themselves to larger females. Monogamy isn’t really a factor in this courtship, however. Over the course of an anglerfish’s lifetime, several males can physically fuse with a female, connecting to her skin and bloodstream and losing their own eyes and organs. Call it love at first glow: these are romantic dreamers, after all. ** Source:** https://twilightzone.whoi.edu/explore-the-otz/creature-features/anglerfish/

Tonight, we'll have a look at the helmetfish!

If you’ve never seen a helmet jellyfish in real life, you’re in good company: it’s one of the few jellyfish (to be accurate, cnidaria) that spends most of its life in the ocean twilight zone. Due to their photo-sensitive red pigment, helmet jellies avoid sunlight like the plague, preferring the frigid depths to the sun’s damaging rays. That red pigment is nonetheless useful for warning would-be predators— and also disguising the bioluminescent prey in their bellies. Like their Coronate cousins, the Atolla jellyfish, helmet jellies display bluish-green lights along a prominently grooved “crown”, a further warning to fish and sea turtles to stay away.

Unlike other jellyfish, these red-helmet types hatch straight from the egg to juvenile stage. They hang out in all oceans except for the Arctic but could be shifting their range northward. In recent years, the species has proliferated in Norwegian fjords as far north as Svalbard, causing some alarm amongst fishermen who feared that these glowing nightly apparitions on the surface would eat up all the juvenile cod and haddock. This unwelcome guest has nonetheless provided scientists with an opportunity to study helmet jellyfish’s habits, which previously could only take place at depth.

Helmet jellyfish lack brains and eyes but make use of a simple sensory “bulb” that detects changes in light. When the sun comes out, that’s the helmet jellyfish’s cue to retreat to the murky safety of the twilight zone. However, scientists have been puzzled by the lack of day-night pattern that most other diel vertical migrators follow. They point to the gradual “darkening” of coastal waters due to nutrient runoff as one reason the helmet jelly might be able to survive the light of day.

Source: https://twilightzone.whoi.edu/explore-the-otz/creature-features/helmet-jellyfish/

Each month, 16 species will go head-to-head in an all-out popularity contest! Throughout the month, species will be pitted against each other, with the victor progressing to the next stage.

The winning species each month will get a custom art piece, available as emojis for now, and eventually, alot more...