WTF? (WHAT’S THAT FISH?) 11: STARGAZER FISH


Star Gazer fish (Adam Rees : Scuba Works)

WTF? (WHAT’S THAT FISH?) 11: STARGAZER FISH

It’s a real shocker! This fish is a serious contender. An A-list horror-fish. The WTF? series has featured some extraordinary, bizarre and frankly unbelievable fish species. Here’s one that might just blow them all out of the water. So to speak. Not only is this fish weird in a number of respects, but it is also dangerous. Behind its eyes it has a special ‘electric organ’ (a “Hammond”?**) that produces a shock when touched. Oh for a superpower like that, even if only to be used defensively. 

“They’re the meanest things in creation,” fish scientist William Leo Smith, who owns a stargazer, told the New York Times. “I was so excited to get it. It’s the worst pet on earth.”

‘Fish out of water’. Note (but do not touch) the area behind its eyes…Northern_Stargazer (Canvasman21 wiki)

The Northern Stargazer Astroscopus guttatus whiles away the long lazy days lying mostly buried by sand, the stargazy eyes on top of its head picking out prey – mostly small fish – to ambush and stuff into its bizarre YKK zip-mouth. It can bury itself in seconds. An adult stargazer may grow to nearly 2-foot of concealed eating machine. They will stay put unless disturbed, confident that a false move by a creature – it could be you in your flippers – will mean it will be in for a shock. 

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10 STARGAZER ATTRIBUTES TO ADMIRE (BESIDES THE ELECTRIC SHOCKS)

  • The strange mouth looks as it does because it is fringed to keep out sand
  • The head-top eyes can be made to protrude to allow a wider field of vision 
  • It ambushes small fish and swallows them whole (see video below)
  • To lure prey, stargazers discharge seawater through their gills… (Reader: why?)
  • It causes the sand to move about – possible lunch is waiting for a fish further up the food chain
  • They are born with eyes on side of the head; they move to the top as they grow from the larval stage
  • They are content to be solitary, except in the Spring (for the usual reasons)
  • Apparently “little is known about the mating behaviours of these creatures”. A pity, I feel.
  • They have no scales, but they make up for that with an impressive 13 anal spines
  • Unimpressed? Well they also have venomous spines near their gills & above their pectoral fins

stargazer-fish.jpg.653x0_q80_crop-smart

WEIRD FISH – AND WHAT’S WITH THE WEIRD NAME?

I wondered that too. The Astroscopus part derives from the Greek, ‘astro’ (star) and Latin ‘scopus’, a conceptual noun combining watching and targeting – think ‘telescope’, or ‘far-target-watching’. The guttatus (L) part simply means spotted or speckled. A Homo guttatus may need mild medical attention.

Stargazer clip (Wideangl)

THOSE ELECTRIC SHOCKS – HOW BAD ARE THEY?

Well. I kinda knew you’d ask so I looked into it. According to the exceptionally cool ‘Monsters of the Deep’ (see credits), the stargazer shock is approximately 50 volts. The British Health and Safety Executive, whose job is normally to interfere with almost every aspect of daily life in the UK (“you are strongly advised not to drink from bottles marked ‘Rat Poison’ portraying a Skull & Crossbones motif, lest disappointment should result”) has assisted: 

A voltage as low as 50 volts applied between two parts of the human body causes a current to flow that can block the electrical signals between the brain and the muscles. This may have a number of effects including: stopping the heart beating properly; preventing the person from breathing; causing muscle spasms.

The exact effect is dependent upon a large number of things including the size of the voltage, which parts of the body are involved, how damp the person is, and the length of time the current flows.

Sadly, you are quite unlikely to find a stargazer in Abaco waters, which lie slightly beyond their fairly limited western Atlantic range. But hop over to Floridian waters, move a bit north, and you might meet one.

**A musical instrument allusion

Credits: Adam Rees / Scuba Works; Canvasmas21 wiki; Nat Geo Kids;  MONSTERS OF THE DEEP (cool underwater site to check out!); Casey Patton / FMNH; Mother Nature Network (inc for video); Wideangl (clip)

HOGFISH: BAHAMAS REEF FISH (31)


Hogfish at cleaning station ©Melinda Riger @GB Scuba

HOGFISH: BAHAMAS REEF FISH (31)

Hogfish. Fisherman’s delight… getting ‘high on the hog’. This wrasse species Lachnolaimus maximus is a reef denizen, especially where gorgonians are found. It has the distinction of being the only known member of its genus, and because it is IUCN listed as vulnerable, there are strict regulations governing bag, size, and gear limits to protect the species from overfishing.

Hogfish ©Melinda Riger @ G B Scuba

The hogfish gets its name from its long ‘pig-like’ snout, coupled with its rootling behaviour on the sea floor for crustacean prey.

Hogfish ©Melinda Riger @ GB Scuba copy ed Hogfish foraging ©Melinda Riger @ GB Scuba

GENDER STUDIES: IT’S COMPLICATED

The hogfish is a sequential hermaphrodite, meaning it changes sex during different life stages. Juvenile hogfish are female, but mature into males at around 3 years old.

Hogfish ©Melinda Riger @ G B ScubaHogfish ©Melinda Riger @ G B Scuba copy

Hogfish social groups are organized into harems, where one male will protect a group of females in his territory and mate with them.

Hogfish ©Melinda Riger @ GB Scuba Hogfish with isopods ©Melinda Riger @ GB Scuba

CAUTIONARY NOTE Capt. Rick, a loyal follower, has made another of his pertinent comments: “A bit of caution is necessary here! There is some history in the Bahamas of mild to severe Ciguatera poisoning from Hogs. Our M.O. was to only eat Hogs no larger than 5 or 6 lbs. Temporary or permanent blindness, paralysis, and even death is possible with bigger Hogs”. Ciguatera is also a problem with, for example, ‘cuda on Abaco. Those caught on the Marls (west) side are ok to eat; those from the east side have to be treated with circumspection…

Hogfish (with isopod above eye) ©Melinda Riger @ GB Scuba

Credits: all fantastic fish fotos – Melinda Riger at Grand Bahama Scuba

SEAHORSES: PREHENSILE TALES FROM THE REEF


Seahorse (Adam Rees / Scuba Works)

SEAHORSES: PREHENSILE TALES FROM THE REEF

It’s a year since I last posted about these amazing little creatures, seahorses. I featured a number of photos by Melinda Riger, a couple of videos, some useful facts about them, and for some reason some useless facts that I came across in researching the post. You can chase it down here: SEAHORSES 1

Adam Rees of SCUBA WORKS is another diver, like Melinda, who combines great underwater experience with wonderful photographic skills. This posts showcases some of Adam’s seahorse photography, and if it doesn’t want to make you explore the reefs, I can’t think what will…

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

Seahorse Range MapMap: Seahorse range (Nat Geo)

Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)

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Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)Seahorse (Adam Rees / Scuba Works)
Seahorse (Adam Rees / Scuba Works)

Seahorse by Alex Konahin

All phantastic photos: Adam Rees / Scuba Works; Range Map, Nat Geo; Lifecycle diagram, Seahorserun; Seahorse GIF, Alex Konahin

BAHAMAS SHARKS: THE MATING GAME & LITTLE BUDDIES


Shark! Melinda Riger copy

BAHAMAS SHARKS: THE MATING GAME & LITTLE BUDDIES

Sharks: apex predators of the deep. Also, kind to the suckers who hang out with them – REMORAS. In the header image you can see a remora hitching a ride on the shark’s back.

Sharks also seem to enjoy, or at least tolerate, the company of tiny fish – tiddlers so small they don’t even count as a snack or even a canapé. Shark & wee fish ©Melinda Riger @ G B ScubaShark & Tiddler ©Melinda Riger @ GB ScubaShark & buddy ©Melinda Riger @ GB Scuba

Check out the shark-jaw shaped wound on the shark just above. And the rather more dramatic ones on the two sharks below. Shark sex can be a rough old game, and sometimes results in moderate or even severe injury to one participant – or perhaps to both.

Shark with mating marks ©Melinda Riger @ G B ScubaShark mating wounds ©Melinda Riger @ GB Scuba

Credits: all great shark photos recently taken by Melinda Riger, Grand Bahama Scuba

SPONGES ON THE REEF: A COLOURFUL MISCELLANY


Brown Tube Sponge ©Melinda Riger @ G B Scuba

SPONGES ON THE REEF: A COLOURFUL MISCELLANY

It’s time to take an up-close look at some of the sponges you may find as you snorkel or scuba round the reefs of the Bahamas. I am always amazed by how bright and colourful they are, and by their many different shapes and sizes. Even the unpromising sounding (slightly medical, even?) BROWN TUBE SPONGE turns out to be fascinating to examine closely. Here are some more sponge species. 

CANDELABRA SPONGECandelabra Sponge ©Melinda Riger @ G B Scuba copy

STOVE PIPE SPONGEStove Pipe Sponge ©Melinda Riger @ G B Scuba

PURPLE VASE SPONGEVase Sponge, purple ©Melinda Riger @ G B Scuba

BRANCHING TUBE SPONGE WITH ROPE SPONGESponges - Branching Tube Sponge with rope sponge ©Melinda Riger @ GB Scuba

PURPLE TUBE SPONGEPurple Tube Sponge ©Melinda Riger @ GB Scuba

PURPLE SPONGE WITH GIANT ANEMONEPurple Sponge : Giant Anemone ©Melinda Riger @ G B Scuba

VASE SPONGEVase Sponge ©Melinda Riger @ G B Scuba

The above sponges represent a fraction of the sponge varieties found on Bahamas reefs. I’ll post some more quite soon. All this has made me want to go for a snorkel. But right now I am 30 miles from the sea. And I have no gear…

HANG ON A MOMENT! WHAT IS A SPONGE WHEN IT’S AT HOME?

It’s really very simple: if you are ever asked the question, just reply “a sponge is a primitive sedentary aquatic invertebrate with a soft porous body that is typically supported by a framework of fibres or calcareous or glassy spicules. Sponges draw in a current of water to extract nutrients and oxygen”.

AND WHAT, PRAY, IS A SPICULE?

You’re having a laugh… if you seriously want to know, read the abbreviated version about them HERE. And admire this microscopic collage of ‘demospongiae spicule diversity’ made available by the wonders of Wiki and the research of about 20 credited scientists.

Demospongiae_spicule_diversity

All photos: Melinda Riger, Grand Bahama Scuba. Tip of the hat to Wiki and scientists

JACKKNIFE FISH: BAHAMAS REEF FISH (30)


Jackknife Fish ©Melinda Riger @ GB Scuba

JACKKNIFE FISH: BAHAMAS REEF FISH 30

The rather uncomfortably ‘double-k’  Jackknife fish is one of 3 types of similar drumfish subspecies of Equetus found in Bahamas waters. The others are the High Hat and the SPOTTED DRUMFISH – the first fish featured in this series. Each of these drumfish species has juveniles that are elegant and delicate, becoming more conventionally fishlike as they grow to adulthood, as the final image shows.

Jackknife fish (juv) ©Melinda Riger @ G B Scuba copy

I always want to stick a hyphen in to separate each k: jack-knife fish. I think it’s an English thing. I have seen, at the other extreme, ‘jack-knifefish’, which looks most weird of all. Checking online, jackknife fish wins by a distance as the correct spelling. 

Jackknife Fish (juv) ©Melinda Riger @GB Scuba

These little fish, typically between 6 and 9 inches, inhabit the coral reefs of the Caribbean, the Gulf of Mexico, Florida and the Bahamas. Juveniles eat plankton and similar organism, graduating to small crabs and shrimps as adults.

Jackknife Fish ©Melinda Riger @ G B Scuba

A FULLY GROWN JACKKNIFE FISH (NOAA)Jackknife fish adult_NOAA_Photo_Library

Like other drumfishes, the jackknife can produce ‘croaking’ or ‘drumming sounds. This involves the fish beating its abdominal muscles against its swim bladder. There’s a lot more to it than my rather simplistic summary, but it’s probably as much as anyone needs or wants to know… The primary reason is believed to relate to mating. Other reasons include ‘low-level aggression’, and keeping in touch with each other in turbid waters.  I prefer the unscientific theory that sheer happiness makes them croak. Here’s a short video of a happy juvenile Jack knife fish (that’s yet another spelling variant…)

RELATED POSTS

Credits: Melinda Riger / GrandBahama Scuba; NOAA

WTF? (WHAT’S THAT FISH) (10): FLYING GURNARD


Flying Gurnard (Adam Rees / Scuba Works)

WTF? (WHAT’S THAT FISH) 10: FLYING GURNARD

Imagine that you are swimming along resplendent in your snorkelling gear (me) – or in scuba gear for the advanced swimmer (you). There, below you, camouflaged against the sea bottom is a fish. A strange-shaped brown sort of creature with odd side fins. As it progresses over the gravelly sand, your immediate reaction is ‘what the…?’ Its fins seem to be turning into… wings. Like this:

Flying Gurnard (Adam Rees / Scuba Works)Flying Gurnard (Adam Rees / Scuba Works)Flying Gurnard (Adam Rees / Scuba Works)

Yes, it’s a flying gurnard. Unlike flying fish, it can’t actually fly through the air. But once its wings are fully spread, it certainly looks as though it could.

Flying Gurnard (Adam Rees / Scuba Works)Flying Gurnard (Adam Rees / Scuba Works)

WHAT’S THE POINT OF THE WINGS IF THE THING CAN’T FLY?

This gurnard species usually gets around using its ventral fins as ‘legs’, with the pectoral fins (‘wings’) close to the body. There seem to be several possible reasons for possessing the ‘sudden-deployment-of-flashy-wings’ superpower. 

  • It surprises and deters predators by movement, turning prospective prey into an apparently different creature
  • Bright or lurid colouring may be a deterrent warning of a foul-tasting or poisonous species  (APOSEMATISM)
  • A creature may actually be harmless and even tasty (as here) but may appear to be unpalateable or poisonous (BATESIAN MIMICRY)
  • In any event, the wings enable the fish to take off from the sea bottom and travel faster by ‘flying’ thought the water to escape a predator

Dactylopterus_volitans Flying Gurnard (cralize wiki)

I had a quick look to see how  scientists in history had depicted this extraordinary fish. The earliest illustration I could find was taken from “Allgemeine Naturgeschichte der Fische (General natural history of fishes),” a 12-volume encyclopedia by author/illustrator Marcus Elieser Bloch (1723-1799), which described all fish species then known to science (and 267 previously unknown) (© AMNH\D. Finnin) sourced from ‘Hyperallergic’
Flying Gurnard

Here’s a short video of a flying gurnard on the move, from ‘Sia Big Fish’

Credits: All main images Adam Rees / Scuba Works with many thanks, except final one ‘cralize wiki’; Hyperallergic for the historic image; Sia Big Fish for the video