Fish

VHS cover

*Fish* is the second episode of the first season of Eyewitness. The topic of the episode is about the world and diversity of both fresh and saltwater fishes, with a primary focus on the bony fishes. The episode aired on 15th August 1994.

Fish is based on a book title that was first published in 1990, and has been republished in 2000, 2005 and 2022.

## Episode

### Introductory sequence

A salmon leaps out of the water and off-screen, leaving the water rippling before the screen fades to white.

### Episode outline

Click here for the full transcript of Fish.

The world of the fish is greater than our own, yet we hardly know it. Fish are far more extraordinary and diverse than any group of animals on land. They live on three-quarters of the planet’s surface and come in more variety than all birds, reptiles, amphibians and mammals combined. The star sign of Pisces, the fish, is a symbol of rebirth and regeneration. Pisces was possibly inspired by the salmon, the king of fish. Across its life, the salmon moves from fresh to saltwater and back again and where the salmon goes, man follows – for over eight thousand years the salmon provided a resource for people along the northwest coast of America.

Five hundred million years ago, fish had no jaws, fins or scales but did have a spine – this feature was so important that without it there would be no other vertebrate animals. From this early prototype grew fins for steering, before some fish changed paths. Some, like sharks and rays, grew a skeleton of cartilage while the vast majority developed a bony skeleton, scales and a swim bladder. These designs have been common in fish for the last hundred million years including the most famous of all fossil fishes, the coelacanth. But in 1938 scientists found that coelacanths were still living off the coast of East Africa.

For its first few months, the salmon stays in the stream of its birth. Once it reaches a few inches in length, it begins to head downstream to the sea, joining others in large shoals. The fish’s body is designed for survival and it has done so to the tune of nearly thirty thousand species, including the ocean sunfish which can lay three hundred million eggs at a time. There are twelve hundred species of catfish living in the South American rainforest, some twice as big as the largest land cat. The Atlantic Ocean has a million, million herring – five times the number of all humans on Earth.

Despite their differences in size and shape, all fish share certain features. A bony skeleton, a swim bladder, fins and gills for filtering oxygen from the water. One organ gives fish a unique sixth sense – the lateral line. This strange tubular, jelly-filled organ along the fish’s side allows the fish to pick up tiny changes in water pressure and movement and instantly sense its surroundings. The scales of a fish are tiny overlapping plates, which provide both strength and flexibility. Fish move with an S-wriggle that starts with tiny movements of the head. There is no known colour that is not found somewhere on the body of a fish. No other group of animals has such a huge difference in size between newly-hatched young and grown adult as the fish, such a difference in bulk as between the dwarf pygmy goby and the whale shark or such a difference in speed between the slow-moving seahorse and the sailfish.

One boundary separates all fish into two clear groups – fresh and saltwater. Few fish can cross this boundary, but the salmon can. At a year old, the salmon enters the ocean. The driving force for all fish behaviour is survival – eat and not be eaten. Many fish eat nothing more than plankton, while parrotfish feed on corals, triggerfish blow water to expose their prey and scorpionfish fool their prey with camouflage. The image of fish gulping their prey down whole inspired the story of Jonah. While men have no defence against being swallowed, fish have all kinds of strange defences. Pufferfish can blow themselves up into a ball, but the most common defence is camouflage, as seen in the razorfish and the open-water fish with countershading. The fish was used as a symbol by the early Christians to hide from persecution. The adult salmon in the ocean gets camouflaged for living in the open sea and begins to feed, grow and swim for thousands of miles. Other camouflaged fish include the Amazon leaf fish, the blenny and garden eel in their hidey-holes and cardinalfish that hide among sea urchin spines.

As with humans, the greatest threats fish face come from their own kind – some fish fight battles over territory and, even if the fish are ill-matched, the territory holder mostly wins. Some battles are against the environment. The icefish of Antarctica has an antifreeze in a translucent plasma instead of blood, while tilapia can survive the great heat of volcanic soda lakes. The strangest fish live in the abyss, where they survive by having feather-light skeletons and a body devoid of air. Many deep-sea fish create their own light with luminous mucous or bacteria. It is the strangeness of many fish that have caught the imaginations of humans and inspired tales of sea monsters and mermaids. A common fish develops just as strangely as these mythical beasts – the flatfish. At birth they look like a normal fish but as they grow one eye migrates across to the other side of the head, they start to swim on their sides and after seven weeks they are a perfectly-camouflaged flatfish. Out in the ocean, the salmon has also changed. It is now two years old, a foot long and has gained salmon pink flesh from a diet of shrimps and smaller fish.

The fish shoal is the supreme underwater community, allowing food and mates to be found easily and providing safety in numbers against predators. Each fish uses its lateral line to move in perfect synchrony with the others in the shoal. Many fish have amazing eyesight, able to identify the patterns of others of their species. Four-eyed fish can see both above and below water simultaneously, while archerfish have such good above-water vision they can shoot down flies with jets of water. The inner ears of fish allow them to orientate themselves, and allows the dottyback to feed while upside-down. Electric eels sense their surroundings with an electric field, and can send out a burst of electricity to kill their prey.

Fish make sounds to communicate with each other. The noises are used to threaten, navigate, find mates and cooperate. Clownfish cooperate with anemones, protecting them from predators in exchange for a home and food scraps while cleaner wrasse valet giant groupers. The strangest relationship is between a goby and a shrimp. The shrimp is excellent at digging burrows but is almost blind, while the goby has keen eyesight but cannot dig its own hole. So, the two move in together with the goby always staying within touching distance of its tenant’s antennae and guiding it home if it gets lost. For man, the main value of fish has been as a source of food with beluga caviar being the most expensive food in the world. This delicacy is made of sturgeon eggs. Man has created a host of superstitions around fish, with fishing communities believing that fish had properties both good and ill.

After six years at sea, the salmon returns to the stream of its birth, guided by memory and sense of smell. They pause at the river’s mouth to change their physiology to a freshwater fish again and start to pair off before their final journey. Many species of fish use displays and colour to attract a mate. Most fish fertilise their eggs outside the body and abandon them to the currents. Some make nests and guard their young as they develop, while the mouthbrooder takes her offspring into her mouth as protection from predators. Seahorses swap the traditional parent roles, with the males carrying their eggs in a brood pouch until they are ready to emerge. Many young fish use their sense of smell to keep in touch with their parents.

In salmon, the sense of smell drives them upstream where they fling themselves through the air across obstacles like waterfalls. Other fish are better-adapted to life out of water. Mudskippers crawl out onto mudflats to catch insects and socialise, the walking catfish can stay out of water for twelve hours as it moves between pools, hatchetfish jump to escape predators while the arowana fish can leap higher than a man to catch prey in the branches above. But none match the salmon in power as it fights its way upstream, dodging predators and not feeding at all on its journey. The salmon finally complete their journey. The female digs a pit in which eggs are laid and fertilised, before the exhausted parents drift back downstream to die. The task of life is now complete, with eggs ready to hatch – just like Pisces, this is a story of rebirth. The fish echoes our own birth, is our earliest living ancestor and rules a world far greater than our own but still beyond our reach.

## Animal species filmed for the programme

### Studio footage

* Atlantic salmon, *Salmo salar*
* Clown triggerfish, *Balistoides conspicillum*
* Cuban hogfish, *Bodianus pulchellus*
* Jaguar cichlid, *Parachromis managuensis*
* Common goldfish, *Carassius auratus*
* Green terror cichlid, *Andinoacara rivulatus*
* Red-bellied piranha, *Pygocentrus nattereri*
* Common lionfish, *Pterois miles*

### Stock footage

* Golden trevally, *Gnathanodon speciosus*
* Garibaldi damselfish, *Hypsypops rubicundus*
* Long-snouted seahorse, *Hippocampus guttulatus*
* Tomato clownfish, *Amphiprion frenatus*
* Tarpon, *Megalops atlanticus*
* Atlantic salmon, *Salmo salar*
* Pacific lamprey, *Entosphenus tridentatus*
* West Indian Ocean coelacanth, *Latimeria chalumnae*
* Ocean sunfish, *Mola mola*
* Schoolmaster snapper, *Lutjanus apodus*
* Sea goldie, *Pseudanthias squamipinnis*
* Tiger shovelnose catfish, *Pseudoplatystoma tigrinum*
* Red-tailed catfish, *Phractocephalus hemioliopterus*
* Atlantic herring, *Clupea harengus*
* Great barracuda, *Sphyraena barracuda*
* Blue damselfish, *Chrysiptera cyanea*
* Pacific blue tang, *Paracanthurus hepatus*
* Flame angelfish, *Centropyge loricula*
* Yellow tang, *Zebrasoma flavescens*
* Orchid dottyback, *Pseudochromis fridmani*
* Saddleback clownfish, *Amphiprion polymnus*
* Discus fish, *Symphysodon aequifasciatus*
* Whale shark, *Rhincodon typus*
* Short-snouted seahorse, *Hippocampus hippocampus*
* Atlantic sailfish, *Istiophorus albicans*
* Common dace, *Leuciscus leuciscus*
* Chevron barracuda, *Sphyraena qenie*
* Red-bellied piranha, *Pygocentrus nattereri*
* Achilles tang, *Acanthurus achilles*
* Bicolor parrotfish, *Cetoscarus bicolor*
* Redtooth triggerfish, *Odonus niger*
* Long-spined sea urchin, *Diadema paucispinum*
* Domino damselfish, *Dascyllus trimaculatus*
* Scorpionfish, *Rhinopias sp*.
* Tub gurnard, *Chelidonichthys lucerna*
* Monkfish, *Lophius piscatorius*
* Sand goby, *Pomatoschistus minutus*
* Hawaiian white-spotted pufferfish, *Canthigaster jactator*
* Dragon moray eel, *Enchelycore pardalis*
* Leafy sea dragon, *Phycodurus eques*
* Razorfish, *Aeoliscus strigatus*
* South American leaf fish, *Monocirrhus polyacanthus*
* Cardinal tetra, *Paracheirodon axelrodi*
* Spotted garden eel, *Heteroconger hassi*
* Cardinalfish, *Apogonidae sp*.
* Midas cichlid, *Amphilophus citrinellus*
* Antarctic icefish, *Channichthyidae sp*.
* Tilapia, *Alcolapia alcalica*
* Fangtooth, *Anoplogaster cornuta*
* Eelpout, *Zoarcidae sp*.
* Splitfin flashlightfish, *Anomalops katoptron*
* Oyster toadfish, *Opsanus tau*
* Atlantic wolf eel, *Anarhichas lupus*
* John dory, *Zeus faber*
* Brill, *Scophthalmus rhombus*
* Eulachon, *Thaleichthys pacificus*
* Harbour seal, *Phoca vitulina*
* Yellow and blueback fusilier, *Caesio teres*
* California sea lion, *Zalophus californianus*
* Largescale four-eyed fish, *Anableps anableps*
* Banded archerfish, *Toxotes jaculatrix*
* Sohal surgeonfish, *Acanthurus sohal*
* Electric eel, *Electrophorus electricus*
* Salvin’s cichlid, *Trichromis salvini*
* Sergeant major, *Abudefduf saxatilis*
* Skunk clownfish, *Amphiprion akallopisos*
* Potato grouper, *Epinephelus tukula*
* Bluestreak cleaner wrasse, *Labroides dimidiatus*
* Hawaiian cleaner wrasse, *Labroides phthirophagus*
* Shrimp goby, *Cryptocentrus sp*.
* Pistol shrimp, *Alpheus sp*.
* Sterlet, *Acipenser ruthenus*
* Blue-spotted mudskipper, *Boleophthalmus boddarti*
* Walking catfish, *Clarias gariepinus*
* Marbled hatchetfish, *Carnegiella strigata*
* Silver arowana, *Osteoglossum bicirrhosum*
* Brown bear, *Ursus arctos*

## Stock footage sources

The Rocketeers (1932) - Mermaid cartoon

Natural World

* Through Animal Eyes (1985) - Archerfish
* Islands of the Fire Goddess (1988) – Dragon moray attacking a Hawaiian white-spotted pufferfish
* Amazon – The Flooded Forest (1989) – Silver arowana leaping for prey
* New Guinea, An Island Apart: Beyond the Unknown Shore (1992) - Tomato clownfish, domino damselfish and scorpionfish, saddleback clownfish, garden eel

Land of the Eagle – The Great Encounter (1991) – Sturgeon

Realms of the Russian Bear: Born of Fire (1992) – Pacific lamprey

Wildlife on One - When the Fish Come In (1992) - Harbour seals catching eulachon

The Living Isles: Island Waters (1986) - Wolf eel eating sea urchin, John Dory, herring

Supersense: Sound Sense (1989) - Sergeant major fish, fish calls

## Credits

* Producer - David Hutt
* Graphics Designer - Alisa Robbins
* Writer - David Hanson
* Script Supervisor - Brian Meehl
* Camera - Jeff Goodman
	+ Assistant - Jeff Wood
* Set Design - Ben Scott
* Production Manager - Peter Thornton
* Production Assistant - Jon Cox
* Production Secretaries - Cathy Wilkin and Caroline Elston
* Unit Manager - Grant Dean
* Researcher - Catherine Gryparis
* Picture Researcher - Martin Willis
* Graphic Design - Caroline Sherry
* Editors
	+ Offline - Chris Godden
	+ Online - Sharon Stiles
* Dubbing Editor - Julie Mitchell
* Dubbing Mixer - Andrew Wilson
* Music - Guy Michelmore
* Executive Producer - Michael Bright,
* Special thanks to:
	+ Hugh Horrex - Landlocked Salmon Ltd.
	+ The Goldfish Bowl

## Making this programme

The main challenge of filming the salmon, the focus animal of the episode, was getting pictures in front of a clean white background. The first attempt happened at a Welsh salmon farm. Here, footage of flowing water was filmed with a pole-mounted camera, but when salmon were put into a flow tank here, the results were not great. Instead, the crew decided to build a clean flow tank in the studio and bring the salmon to them. After some mishaps with the plumbing of the tank, it was finally ready and the salmon were comfortable in the tank. Finally, footage of a salmon against a clean blue background was achieved, which could then allow the fish to be multiplied and the blue background to be turned white. Finally, the model is shown being told by the director how to demonstrate the perfect S-wriggle that fish use when swimming.

## Home media releases

As well as being released on VHS, Fish was also released as part of the DVD release in the USA.

Fish America-release DVD cover

**Writing staff**: Anne MacLeod • Ben Southwell • Ben Steiner • Brian Meehl • David Hanson • David Stafford • David Helton • George Bloom • Lynette Singer • Mike Tomlinson • Paul Thomas • Stan Cullimore
**Directors**: Gavin Maxwell • Justine Kershaw • David Hutt • Andrew Jackson • Justin Hardy • Ludo Graham • Jerry Foulkes • Derek Hall • Sanjida O'Connell • Caius Julyan • Bonni Cohen • Leanne Pooley • Edwina Vardey • Alexandra Beazley • Sam Hodgkin • Karen Walsh • Jack Weber • Richard Simkin • Alex Hearle • Brian Cummins • Ben Southwell
**Composers**: Guy Michelmore (season one) • Guy Dagul (seasons two and three)

**Season One**: Cat • **Fish** • Horse • Dog • Jungle • Bird • Amphibian • Insect • Shark • Elephant • Reptile • Dinosaur • Skeleton
**Season Two**: Desert • Tree • Ape • Mammal • Butterfly and Moth • Volcano • Rock and Mineral • Seashore • Pond and River • Weather • Arctic and Antarctic • Prehistoric Life • Shell
**Season Three**: Flight • Bear • Sight • Island • Survival • Mountain • Monster • Human Machine - Plant • Ocean • Planets • Life • Natural Disasters