Friday Fish Time
Posted: June 7, 2013 Filed under: Friday Fish Time | Tags: Amazon, candiru, fish, friday fish time, parasite Leave a comment »
Common name: Candiru. Scientific name: Vandellia cirrhosa. Family: Trichomycteridae. Image: Dr. Peter Henderson.
Also known as the toothpick fish or vampire fish, the Candiru is a slender, translucent parasite. These creepy critters are native to the Amazon Basin and live in the gills of larger fish, feasting on their blood.
While some Candiru species can grow up to 40 centimetres long, the majority are quite small. It’s these smaller species that are famous for their alleged tendency to invade and parasitise the human urethra, although the truth to this story remains unknown.
Nonetheless, if you plan to swim in the Amazon, it might be a good idea to go to the bathroom first.
Friday Fish Time
Posted: May 24, 2013 Filed under: Friday Fish Time | Tags: biodiversity, environment, fish, Fishing, friday fish time, Oceans Leave a comment »
Common name: Mackerel Icefish. Scientific name: Champsocephalus gunnari. Family: Channichthyidae.
Mackerel Icefish: Right. It is starting to get a bit cold around the countryside so I thought this may be of interest.
It is a fish found only in the Southern Ocean and are mainly Heard and McDonald Islands, and islands in the south Atlantic such as South Georgia.
They are found in depths up to 700m with older juveniles and adults forming large schools at or near the sea bottom or mid-water range of the water column, feeding on krill and small fish.
They grow quite quickly and mature at a length of between 22cm to 26cm after about three or four years. They grown to about 35cm.
Apparently the flesh is white and firm like the King George Whiting but with a higher oil content. They are good for grilling, baking or steaming.
Friday Fish Time
Posted: May 17, 2013 Filed under: Friday Fish Time | Tags: biodiversity, ecosystems, environment, fish, friday fish time, marine, Oceans Leave a comment »
Common name: Moon Jellyfish. Scientific name: Aurelia aurita. Family: Ulmaridae.
Moon Jellyfish: It is rare for these to live more than six months in the wild but they are really interesting.
All species in the genus are closely related and is hard to pick them apart except by genetic sampling.
They grow to about 25–40cm in diameter and can be recognized by its four horseshoe-shaped gonads, easily seen through the top.
It is not really a strong swimmer and it mainly drifts with the current feeding on plankton, fish eggs, small organisms and molluscs. It captures food with its tentacles and scoops it into its body for digestion.
Moon Jellyfish are found throughout most of the world’s oceans, from the tropics to as far north as latitude 70°N (runs through the middle of the US and Spain) and as far south as 40°S (runs through Tasmania).
It has also been found in waters as cool as 6C to as warm as 31C.
They do not have any respiratory parts such as gills, lungs, or trachea so it respires by diffusing oxygen from water through the thin membrane covering its body.
Friday Fish Time
Posted: May 10, 2013 Filed under: Friday Fish Time | Tags: beached as, killer whale, new zealand, orca, sea monster Leave a comment »
Common name: killer whale. Scientific name: Orcinus orca. Family: Delphinidae.
Image: YouTube/Elizabeth Ann
Today we’re crossing the Tasman for a mystery of the deep. Fishy remains became famous last week when a strange carcass washed up on a New Zealand beach and made it big on YouTube under the guise of a “sea monster”.
Speculation about the prehistoric origin of the “monster” was atwitter until one of New Zealand’s marine mammal experts stepped in (cue the Get Smart theme song). New Zealand Museum’s Anton van Helden told NZ TV that it could be identified as an Orca (a.k.a. killer whale), due to a distinctive flipper. Killer whales are found in all oceans and it’s estimated that the largest population lives in Antarctic waters. New Zealand’s Bay of Plenty was certainly full of surprises, as this YouTube clip shows:
It’s unknown why the killer whale died or washed up on shore. I imagine if it could talk, it would probably say something like this…
Friday Fish Time
Posted: May 3, 2013 Filed under: Friday Fish Time | Tags: biodiversity, environment, fish, Fishing, friday fish time, Goolwa, Oceans Leave a comment »
Shaw’s Cowfish
The photo above was sent in by a friend of a friend who came across the dead fish at Goolwa in South Australia this week and was unsure what it was.
I sent it to Alastair Graham who is the Fish Collection Manager at the Australian National Fish Collection in Hobart. As expected Alastair was a font of fishy knowledge.
“The photo does not show all the diagnostic characters, however I would say that it is most probably a Shaw’s Cowfish (Aracana aurita). They are normally found on coastal rocky reefs and seagrass areas at 10-160 metres. Not being strong swimmers, they are often found washed-up after storms.”
I had to laugh when Alastair said it was was not a good swimmer – seems pretty important to a fish…
Anyway, they are found around southern coastal waters of Australia from central New South Wales to south west Western Australia.
Friday Fish Time
Posted: April 26, 2013 Filed under: Friday Fish Time | Tags: anglerfish, fish, friday fish time, Gulf of Mexico, Louisiana, pancake batfish 1 Comment »Nananananananana batfish! Pancake batfish that is.
Common name: Louisiana pancake batfish. Scientific name: Halieutichthys intermedius. Family: Ogcocephalidae. Image: Flickr.
The Louisiana pancake batfish is a newly discovered species native to the Gulf of Mexico. It was only just before the big oil spill in 2010 when these cool critters were first found. Unfortunately the fate of their population following the disaster is not yet known.
It’s no surprise where the name pancake batfish comes from. These funny looking fish have flat bodies with an enlarged head and trunk which form a round disc shape. They are small enough to fit in the palm of your hand and are about as thick as a fluffy pancake (probably not as tasty though).
An artist’s impression of the pancake batfish – the resemblance is uncanny! Image: Bryson Fink.
And if you thought turtles were awkward, you haven’t seen these guys move. Pancake batfish have small foot-like fins, complete with elbows, which are used to ‘walk’ along the ocean floor in a bizarre motion – kind of like a crawling bat. Needless to say, they aren’t the most graceful swimmers.
Luckily they are well camouflaged, so it isn’t too hard to get some grub. Being a member of the anglerfish family, a simple wiggle of their dangling ‘lure’ is enough to capture unsuspecting prey without having to clumsily flounce around the sea bed.
While they might not be the prettiest or most elegant fish, they are quite popular. In fact, the Louisiana pancake fish was recently named as one of the Top 10 New Species of 2011, right after being described as “remarkably hideous (in a good way)”. I’d take that as a compliment…
Friday Fish Time
Posted: April 19, 2013 Filed under: Friday Fish Time | Tags: Antarctic Ocean, blood, fish, friday fish time, ocellated icefish, Tokyo, vertebrate Leave a comment »TGIFFT! (Thank God It’s Friday Fish Time!) Here’s a riddle to get you in the fishy spirit:
Q: What do you call a fish with clear blood?
A: An Ocellated Icefish.
Common name: Ocellated Icefish. Scientific name: Chionodraco rastrospinosus. Family: Channichthyidae. Image: Wikimedia Commons.
Okay, so that was pretty lame. But how cool does that fish look? Cool enough to distract you from my poor attempt at a riddle…right?
The exotic Ocellated Icefish lurks about in the chilly depths of the Antarctic Ocean, and as you’ll soon find out, it’s certainly one of a kind.
Aside from being able to survive in such an extreme environment, these fascinating aquatic vertebrates also lack haemoglobin. This could explain why their blood is clear, since haemoglobin gives most blood its red colour. You’d think the fish would have a hard time getting by without this essential protein, but amazingly their circulatory system does fine without it. In fact, these guys have super strong hearts that are larger and pump blood five times faster than most other fish.
And it gets weirder. The Icefish also lack scales, which some say makes them sort of like the Sphinx cat among fish.
To this day, nobody knows how these fish evolved in such a strange way.
If you want to see them in person, you’ll have to take a trip to Tokyo Sea Life Park - the only place in the world where a male and a female specimen are living in captivity. Otherwise you could go for a casual dive in the Antarctic Ocean.
Just recently, the two lovebirds in Tokyo successfully spawned – which was a world first for this species. Scientists are hoping this might help unlock some of the fish’s deep, dark secrets.
I’ve got to say though, for an unusual fish they sure are boring! Take a look at this video and see if you agree.
Friday Fish Time
Posted: April 12, 2013 Filed under: Friday Fish Time | Tags: anglerfish, fish, friday fish time, Humpback anglerfish, Oceans, sea devil Leave a comment »Humpback Anglerfish: Ah, the anglerfish. Such a fascinating and (let’s face it) unfortunate looking creature.
Common name: Humpback Anglerfish. Scientific name: Melanocetus johnsonii . Family: Melanocetidae. Image: Bruce Robinson, Corbis.
Also known as the ‘black seadevil’, the Humpback Anglerfish lives among the darkest depths of the Atlantic and Antarctic oceans. Interestingly, male and female anglers are completely different in their characteristics.
Only the female fish has the distinctive ‘fishing rod’ style dorsal spine hanging above its head, complete with a fabulous bio-luminescent tip that acts as a lure to attract prey. The glow is made possible by the millions of bacteria that live inside the spine – how very hygienic. With a simple wiggle of this glowing outgrowth, the anglerfish can draw her prey close enough to devour them in one bite. Her expandable stomach and jaws means she can swallow prey up to twice her own size.
Male anglers, on the other hand, aren’t so special. They are about ten times smaller than females and lack the specky fishing rod spine. Without this asset, they have a pretty hard time salvaging food. To make matters worse, when the male angler matures, its digestive system degenerates making it impossible to feed on its own. This means it has no choice but to become a permanent parasite.
The poor male anglerfish is just one tenth of the female’s size. Image: Mudfooted.
The male uses its small hook-shaped teeth to attach itself to any female it can find. Once he bites into her skin, he releases an enzyme that dissolves the skin of his mouth and the female’s body. The two become fused together and their blood vessels combine as one (aww, how romantic). The male will spend the rest of his life joined to the female, getting all of his nourishment from her body. Talk about clingy…am I right ladies?
The female can carry up to six males on her body at one time – so when she’s ready to spawn she can easily take her pick of the lot. Looks like they’ve got it pretty easy unlike the poor blokes!
Here’s what this would look like if the fish were human:
Friday Fish Time
Posted: April 5, 2013 Filed under: Friday Fish Time | Tags: Amazon River, fish, friday fish time, piranha, red bellied piranha Leave a comment »
Common name: Red-bellied piranha. Scientific name: Pygocentrus nattereri. Family: Characidae.
Red-bellied piranha: Don’t let their glittery scales fool you – piranhas are one school of fish you don’t want to mess with…or so we’ve been led to believe.
There are over 20 different species of piranha, most of which live in the Amazon River Basin. Surprisingly though, the majority pose no real threat.
Red-bellied piranhas are possibly the most misunderstood fish in the world. Despite their fierce and aggressive reputation (thanks to popular culture), these little critters feed mainly on fish, insects, plants, fruits and small aquatic invertebrates.
As you might have presumed from the name, the fish have a reddish tinge on their bellies, while the rest of the body is grey with silver flecked scales. The male belly tends to be a deeper, more intense red while female bellies appear more yellow. They generally grow up to 33cm in length and weigh a tiny 3.5kg.
But don’t be fooled by their size. Their powerful jaws and sharp, triangular teeth allow the fish to bite through food with incredible force and ease. It’s no surprise why the name ‘piranha’ literally means “cuts the skin” in the native South American language Tupi-guarani.
Occasionally, the fish can go into a ‘feeding frenzy’, where they hunt large groups of prey and strip them clean within a matter of minutes. These frenzies don’t tend to be random attacks though – they are often the result of aggravation or starvation when food is scarce. Long story short, if you ever come across a piranha, don’t do this:
Friday Fish Time
Posted: March 29, 2013 Filed under: Friday Fish Time | Tags: biodiversity, ecosystems, environment, fish, Fishing, friday fish time, marine 1 Comment »
The anatomy of Lampanyctodes hectoris
(1) – operculum (gill cover), (2) – lateral line, (3) – dorsal fin, (4) – fat fin, (5) – caudal peduncle, (6) – caudal fin, (7) – anal fin, (8) – photophores, (9) – pelvic fins (paired), (10) – pectoral fins (paired)
As it is Good Friday I thought I would look into the association of fish with Christianity and religion in general. However, that turned out to be way too hard and full of potholes I just could not be bothered navigating around – and I’m trying to pack the swag for camping.
So, rather that concentrate on one fish I have “researched” Wikipedia for a description of all fish.
Here you go:
A fish is any member of a paraphyletic group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups. Most fish are ectothermic (“cold-blooded”), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., gulpers and anglerfish). At 32,000 species, fish exhibit greater species diversity than any other group of vertebrates.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
Friday Fish Time
Posted: March 22, 2013 Filed under: Friday Fish Time | Tags: biodiversity, ecosystems, environment, fish, Fishing, freshwater, friday fish time, Lake Baikal, marine Leave a comment »By Sarah Wilson
Today is World Water Day. In the spirit of this day I would like to pay homage to all things freshwater. In particular I would like to draw your attention to a peculiar fish found in the depths of the largest freshwater lake in the world : behold the Golomyanka.
OK, I admit it is a rather unassuming looking fish, but looks can be deceiving. Golomyankas, also known as Baikal oilfish, are only found in one place in the world – Lake Baikal . This UNESCO World Heritage Listed Lake is located in nippy Siberia. It is 25 million years old, contains one fifth of the world’s unfrozen freshwater, and is home to a staggering number of plant and animal species found nowhere else in the world. Earning it the nickname of ‘the Galapagos of Russia’.
As for the fish, it’s pretty amazing too:
The nerpa seal – yes, the Golomyanka does seem to contain a lot of fat….
Amazing fact No. 1: They are the world’s most abyssal fish. This means they live in the entire range of depths found in Lake Baikal. That’s a span of up to 1700m below the surface of the water. The pressure of going to these depths would easily crush a human.
No. 2: They rapidly melt in sunlight leaving only oil, fat and bones. (Imagine that!)
No. 3: It is one of only a few viviparous fish in the world. Viviparous means that it doesn’t lay eggs, but gives birth to live young . It gives birth to up to 3000 larvae at a time.
No. 4: They are a primary food source for the Lake Baikal’s nerpa seal. One of the few exclusively freshwater seal species found in the world.
No 5: They have a high fat content (over a third of their body weight is made up of fat). Native Siberians have been known to use them as fuel for their lamps.
Friday Fish Time
Posted: March 15, 2013 Filed under: Friday Fish Time | Tags: biodiversity, ecosystems, environment, fish, friday fish time, marine, Nature, Oceans Leave a comment »
Common name: Bareskin Dogfish. Scientific name: Centroscyllium kamoharai. Family: Etmopteridae.
Bareskin Dogfish: I have an affinity with this dogfish. Little is known about how it works or the environment it inhabits. It is actually a shark and has so far only been found near Japan, along the Australian coast from about Brisbane to Hobart and in a relatively small area from Perth to the north.
Apparently they are dark in color with white-tipped fins, which suggest the pictured specimen above is either an albino or just a very crook sample.
According to what I could find out about them they have no anal fin (who would want one) and has grooved dorsal spines with the second larger than the first. It has a blunt nose, large eyes and large nostrils. It grows to a a maximum of about 45cm.
They are found in a depth range of 500m to 1200m.
It has litters of three to 22 pups.
And that is about where the information on this thing ends: No information on the reproductive cycle, no information on annual fecundity, gestation period, age at maturity or longevity.
Friday Fish Time
Posted: March 8, 2013 Filed under: Friday Fish Time | Tags: friday fish time, FRV Derwent Hunter, Swordfish 3 Comments »
Common name: Swordfish. Scientific name: Xiphias gladius. Family: Xiphiidae.
In a week where we have been talking about Australia in 2050 and our future research vessel, it seemed refreshing to take a dip into the archives.
Meet the majestic FRV Derwent Hunter. The 72ft schooner was purchased by CSIRO in 1950 and was used for everything from shark tagging to plankton studies and deep sea fishing.
The FRV Derwent Hunter. Rigged as a schooner, it measured 72ft, had a 72HP diesel engine and distinctive red sails.
In 1959 the Derwent Hunter cruised South-East Australian waters to see if there was a relationship between the distributions of southern bluefin tuna and the type of water where they were caught. Our tuna research reeled in this huge swordfish, which we couldn’t resist as our fish of the week.
Swordfish are found widely in tropical and temperate parts of the Atlantic, Pacific and Indian oceans, and have an interesting way of keeping warm in the cooler waters of South-East Australia. They have special organs to heat their eyes and brain, that have been measured at 10-15°C above surrounding waters. If you’ve ever used RipCurl’s heated wetsuit, you’ll understand how this can be wonderfully toasty.
The heating gives the Swordfish better vision and increases their ability to catch prey, although didn’t help them avoid the longlines of the FRV Derwent Hunter.
Swordfish caught while tuna fishing on the FRV Derwent Hunter in 1959. L-R the crew Billy Elsemere, Reg Bradley,Ken Smith and captain George Reid.
Friday Fish Time
Posted: March 1, 2013 Filed under: Friday Fish Time 3 Comments »The Australian fish world was abuzz this week with the release of FishMap, an online mapping tool that allows humans to check out where their favourite marine fish are living these days. You can see what fish are living in your area and what depth they tend to hang out at, just in case you wanted to drop by. The tool gives fish around Australia an unprecedented ability to compete for the attentions of people. With 4500 Australian marine fishes listed, including our 320 sharks and rays, there are sure to be plenty jostling for your affection.
Here are some of the stars of FishMap and a taste of what’s out there in our marine environments:
Friday Fish Time
Posted: February 22, 2013 Filed under: Friday Fish Time | Tags: biodiversity, caviar, environment, fish, Fishing, friday fish time, sturgeon Leave a comment »
Common name: Sturgeon Whiptail. Scientific name: Mataeocephalus acipenserinus. Family: Macrouridae.
Sturgeon Whiptail: I was kicking back watching one of those fishing shows on TV the other day and they were somewhere in Canada catching sturgeon – and they were huge.
Think sturgeon. Think caviar.
So, does Australia have any of these? Nup. We have this thing above, but I have got to say they are a huge disappointment. Yeah I know – all creatures great and small – but this Whiptail just doesn’t cut it. They are actually part of the grenadier family and seem to be cashing in on the sturgeon name.
They grown to a maximum length of about 20cm and are found in depths of between 400m and 1300m off the northern Australian coast.
That’s about it – they are small and ugly.
The REAL sturgeons are bottom-feeders and are usually found in river deltas and estuaries. Some are entirely freshwater and a few venture into the open sea beyond near coastal areas. Several species of sturgeons are harvested for their roe, which is made into caviar.
Sturgeons appeared in the fossil record about 200 million years ago, around the very end of the Triassic, making them among the most ancient of actinopterygian fishes. True sturgeons appear in the fossil record during the Upper Cretaceous.
They are slow growing and can live to 100+ years and can grow to over 5m in length. They are partially covered with bony plates called scutes rather than scales. They also have four barbels – the feelers in front of their mouths – which don’t have any teeth. These are used to drag along the bottom to help them find food and navigate.
Now, THIS is a sturgeon!
This was caught in the Fraser River in British Columbia, Canada. It came in at 3.6m and an estimated weight of 499kg.
