Unfishy Fish

     What do you think of when someone says “fish”? The image of a salmon or goldfish probably pops into your mind. Or perhaps a colorful tropical reef fish. Odds are, you’re not thinking of a lipstick wearing, pancake shaped animal with frog feet and a long, pointy nose. You’re most likely not thinking of a Toblerone shaped shark with swirly nostrils either. The fact is, evolution doesn’t care what your idea of a fish is. It’s going to go with what’s successful and if it looks like a nightmare clown, so be it. Evolution doesn’t have a goal or a grand plan. What happens will happen and if something works, it persists.

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A generalized fish body plan.

     So here we are with and ocean of oddities to explore. To start with, let me introduce you to something that looks more or less like a ‘proper’ fish, but didn’t get the memo about how to swim like one. Enter, the razorfish (Aeoliscus strigatus). This fish is elongated and laterally compressed, giving it a razor thin appearance, hence the name. It feeds on tiny zooplankton such as brine shrimp as it hides among corals and seagrasses. Razorfish swim vertically in small schools with their snouts pointed down at all times. It is not known exactly why they do this, but it’s certainly entertaining to watch. With razorfish, it’s always a synchronized swim show. For the razorfish, the warm waters of the western Indo-Pacific are the perfect place to engage in these underwater ballets.

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A school of razorfish.

     Another weird, warm water inhabitant to be featured here is at home in the lower estuary of Derwent River in Tasmania and several other locations along the southeastern coast of Australia. Unfortunately, it is now critically endangered because of a multitude of factors including a low reproduction rate, habitat destruction, and suspected predation by an introduced sea star. The spotted handfish (Brachyonichthys hirsutus) has a sail like dorsal fin and large, webbed ‘hands’ which it uses to walk along the silty bottom. It belongs to of the order Lophiiformes, along with other strange members like deep sea anglerfishes and frogfish.

spotted-handfish

Spotted handfish.

Unlike many other fish, which hatch out as larvae that further develops outside the egg, spotted handfish emerge as tiny, fully formed versions of their parents. Rather than floating among the plankton of the open water, these babies stick to the sandy floor and live out the rest of their lives there. The peculiar reproduction habits of this fish are exactly what make it vulnerable to the northern Pacific sea star (Asterias amurensis). Before they become fish, the eggs are attached to stalked sea squirts and other vertical organisms that are extremely appetizing to the star. As a consequence, the eggs are devoured along with the sea star’s target prey. Conservation efforts have since been set in motion to save this unique Australian animal. Along with a captive breeding program and hope of reintroduction, there has been some success with providing manmade alternatives for the handfish to lay their eggs on. Handfish have been using these sticks and as a result fewer eggs are lost to the ravenous sea star. The spotted handfish is a protected species and one of the benefits that comes with that status is efforts to reduce silt and pollution within the Derwent River estuary and restore quality to the fish’s habitat. Even though the spotted handfish is still very much at risk, there is hope for it and therefore hope for other endangered animals.

     Our next fish is not nearly as well known as some of the others on this list. It doesn’t live in warm water either and instead spends its life thousands of feet down on continental slopes where the majority of the sun’s light fails to reach. Chaunax pictus, the pink frogmouth, is another member of the anglerfish order. It can only be glimpsed from the window of a submersible or through the eyes of an ROV sent to explore the depths of the ocean. There is virtually no data about its reproductive habits, life cycle, or population trend. One study of C. pictus in the Arabian Sea observed that it only eats small shrimps. With a dearth of information like this, the most interesting thing about this fish is its appearance. Imagine a squat, pink or orange potato with a scowl to rival that of Grumpy Cat and you’re pretty much there.

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Pink frogmouth

The pink frogmouth uses its odd fins to crawl around over rocky slopes in search of prey when it’s not sitting motionless, camouflaged as a pissed off lump of cheese. The Chaunax in the video below starts walking at 1:55 if you’d like to see it in action.

     Slightly more attractive, though no more at home in shallow water, is the Caribbean roughshark (Oxynotus caribbaeus). One of the few fish on here that isn’t part of the anglerfish order, it is closely related to the more commonly seen prickly dogfish (Oxynotus bruniensis). Almost nothing is known about the natural history of the Caribbean roughshark other than that it inhabits the upper continental slope from the Gulf of Mexico to Venezuela. This shark has sloping sides and a concave belly that give it the appearance of an animal that was forced through a triangular Play-Doh mold. Its sandpapery skin is pale gray to white with dark brown patches, which actually make it quite striking.

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Caribbean roughshark.

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Swimming Toblerone

The prickly dogfish is less showy, but just as oddly shaped. The scales are raised and conical like studs making it truly deserving of its name. Like the Caribbean roughshark, it is small, only reaching a little over two feet from snout to tail. It has a mouth reminiscent of the cookie cutter shark and feeds on the eggs of other Chondrichthyans (cartilaginous fish). Prickly dogfish can be found in shallower water than roughsharks, but are also seen at great depths.

Ichthyology

Prickly dogfish.

Sharks are generally thought of as sleek and streamlined predators designed to kill, but these two species just reinforce the fact that every family has some real weirdos.

     Now we get to my personal favorite, and arguably weirdest of this group, the batfish. Despite their name, the batfishes, or Ogcocephalidae, don’t resemble bats in the least. In fact, they might be more suited to the name clownfish if that weren’t already claimed by the well known anemonefish everyone knows and loves from “Finding Nemo”. All batfishes are strange looking, but the red lipped batfish (Ogcocephalus darwini) takes the cake. With flattened body, nose-like face protrusion, and bright red lipstick looking like it was put on while drunk, this fish could be mistaken for a clown at a sorority party gone a little too far.

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Hey there, beautiful!

Also called the Galapagos batfish, it does indeed inhabit the warm, shallow waters of the Galapagos islands and nowhere else. It can be found swimming very awkwardly along reef edges over sandy substrate where its prey resides. Much of the time, it doesn’t even bother to swim. Instead, it crawls along the sand like a squashed frog and pauses frequently to lure prey.

Whereas many of its angler relatives use a nifty lure that comes out near the head region, the red-lipped batfish has one just above its lips under that pointy nose, which makes it look exactly like it has a perpetual booger hanging out of its nostril. The lure is bobbed up and down, acting as both a visual and chemical attractant for small invertebrates and a turn off for anyone else.

     Of course, it’s not this poor batfish’s fault that it looks so ridiculous. It has evolution to thank for that. For some reason, this strange body plan worked and stuck around as a result. The same goes for the rest of the fish featured in this article and so many more that it would be impossible to cover them all here. This was just a taste of the numerous odd ducks of the fish world and hopefully another motivation to keep exploring the stranger things out there. You never know what we might find next.

References:

1. Clemens, Danny. “The Red-Lipped Batfish Is Always Ready for a Night on the Town.” DSCOVRD. Discovery Channel, 07 July 2015. Web. 21 July 2016.

2. Montoya, P. Zelda, et al. “The Natural History and Husbandry of the Walking Batfishes (Lophiiformes: Ogcocephalidae).”DRUM and CROAKER: 6.

3. Schulz, Katja. “Galápagos Batfish – Ogcocephalus darwini.” Encyclopedia of Life. EOL, 2014. Web. 21 July 2016.

4. Rijnsdorp, A. D., M. Costa, and T. Munroe. “Chaunax pictus (Pink Frogmouth, Redeye).” IUCN. IUCN Red List of Threatened Species, 2015. Web. 21 July 2016.

5. Leandro, L. “Oxynotus caribbaeus (Caribbean Roughshark).” IUCN. IUCN Red List of Threatened Species, 2004. Web. 21 July 2016.

6. McGrouther, Mark. “Prickly Dogfish, Oxynotus bruniensis.” Australian Museum. Australian Museum, 2 Dec. 2013. Web. 21 July 2016.

7. McGrouther, Mark. “Spotted Handfish, Brachyonichthys Hirsutus.” Australian Museum. Australian Museum, 3 Sept. 2015. Web. 21 July 2016.

8. “Spotted Handfish (Brachyonichthys hirsutus).” Arkive.org. Wildscreen, n.d. Web. 21 July 2016.

9. Capuli, Emily Estelita. “Aeoliscus Strigatus.” FishBase. Ed. Roxanne Rei Valdestamon. Sea Around Us, n.d. Web. 21 July 2016.

Photo and Video Links:

1. http://evolution.berkeley.edu/evolibrary/article/fishtree_02

2. http://les-z-animaux.e-monsite.com/k/poissons-marins-tropicaux/autres-poissons-marins-tropicaux/poissons-lapins-et-poissons-rasoirs/poisson-rasoir-aeoliscus-strigatus.html

3. https://www.youtube.com/watch?v=PN9Rc5DrOzw

4. http://www.arkive.org/spotted-handfish/brachionichthys-hirsutus/

5. http://www.uniprot.org/taxonomy/242967

6. https://www.youtube.com/watch?v=WC69Iq8oMlo

7. http://shark-references.com/species/view/Oxynotus-caribbaeus

8. http://www.wikiwand.com/en/Oxynotus

9. https://australianmuseum.net.au/prickly-dogfish-oxynotus-bruniensis-ogilby-1893

10. http://www.natgeocreative.com/photography/1231868

11. https://www.youtube.com/watch?v=X9inncLXAHg

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