Mrs Evans Creatures of the Deep Analysis of

Mrs. Evans: Creatures of the Deep

Analysis of Animal Adaptations

Long-nosed Chimaera

Vampire squid

Coffinfish

Giant Isopod

Giant Squid

Gulper Eel

Angler

Dragonfish

Fangtooth

Viper fish

External Fish Anatomy

Types of caudal fin • Lunate, crescent • Fast, rapid swimmers

Types of caudal fin • Round • Strong swimmer, slower

Types of caudal fin • Forked • Constantly moving

Types of caudal fin • Truncate • Strong swimmer, slower

Types of caudal fin • Lanceolate (pointed) or leptocercal (long whip like) • Wriggling, weak swimmer, ribbon-like body

Types of caudal fin • Sunfish • Small or continuous with body, • Weak swimmer

Mouths

Mouth • Terminal (at the end of the snout), symmetrical, anterior • Feeds throughout the water • Walleye, whale shark, northern pike

Mouth • Angled upward/longer lower jaw, superior, dorsal • Feeds on prey it sees above it; small fish, or aquatic insects, often at surface of water • smallmouth bass,

Mouth • Ventral, inferior (under the head) Under the snout/longer upper jaw • Feeds off the bottom Feeds on prey it sees below it; usually feeds off the lake or river bottom • Ray, hammerhead

Mouth • Sucker-shaped, subterminal • "Vacuums" up food off the bottom; eats aquatic insects, vegetation • Sucker, sturgeon

Mouth • Strong jaws and welldeveloped teeth • Feeds on other fish • Northern pike, walleye, Viper fish

Mouth • With barbels • Feeds off the bottom; Can sense food in murky water • Catfish, bullhead, stonecat, sturgeon

mouth • Thin mouth (butterfly fish) good for getting small invertebrates from cracks and crevices

Eyes

Eyes • Large • Feeds by sight • Coloussal squid, Vampire Squid

Eyes • Small • Likely feeds off the bottom and relies on barbels to detect food • Whale shark

eyes • Fish looks forward • Swims through water column • Food it eats is caught in front of it

eyes • Fish is called a stargazer b/c it has upward, tubular eyes • Bottom dweller but feeds on fish above it

eyes • Eyes are on the side, can easily pick up movement in the water • Feeds on fish as it swims through the water column and can see all around its body; front, back, upward, downward

Spines • For protection or to stiffen fins for swimming • Stone fish, lion fish, puffer, knight fish

Body Shape • Rounder, flat bellied, depressed (Flattened from top to bottom) • Feeds off or rests on the bottom; less conspicuous to predators • Flounder, skates, rays

Body Type • Oval, fairly long • Prefers more open water or a few weeds • Walleye

Body Shape • Oval, very long, eel-like • Fast-moving in quick bursts; Agile around rocks and weeds, lie-in-wait predator • Northern pike, pickerel

• Thin, shorter, discshaped, laterally compressed • Agile around rocks/weeds; round shape harder for predators to swallow • Angel fish Body Shape

• Torpedo-shaped (fusiform) • Stream-lined for high speed or swimming in currents • Tuna, rainbow trout Body Shape

Scales • Large • Used for protection; speed not needed to catch food • Carp, sucker

Scales • Small or nonexistent • Fish more streamlined and fastmoving to catch prey • Agnatha, Northern pike, catfish, burbot

Coloration • Fairly uniform, no markings • Swims in open water

Coloration • Stripes (disruptive coloration) – The patterns and lines break up the outline of the fish • Hides in weeds for protection or to ambush prey • Perch

Coloration • Mottled • Hides in rocks or on bottom • Northern pike, young sturgeon

Coloration • Dark on top • Less visible to predators above it • Light colored belly • Less visible to predators below it • shark

Coloration

Coloration • Eye Spots (A form of mimicry, the eye spot draws attention away from the head)

Pacific Viperfish

Pacific viperfish feeds on lanternfish and squid. It has a very large mouth and fang-like teeth. Its size ranges from 22 -30 cm. Two rows of photophores. Look at the long, thin ray on the back (dorsal) fin. How might the ray help attract a tasty meal?

This squid can grow to 30 cm in length. Its photophores adjust to match the ocean twilight. It can move very quickly forward or backward. The two longest tentacles grab and hold its prey. The smaller tentacles move the prey to its mouth. The eyes are of different sizes…. Scientists don’t know why.

Very common in the deepwater. It lives where there is some light. . . very large eyes. Verical migrator. Photophores It grows to about 13 cm in length.

10 cm in length. The "lure" is a large photophore. It may help attract prey. It is hard to find and keep mates in the deep sea. They mate for life.

hatchetfish small (6 cm) has upward facing eyes. upward facing mouth can grab its prey. The hatchetfish has photophores on the bottom side. The light helps hide its outline. Other fish swimming below the hatchetfish see the light and not the hatchetfish's silhouette. …countershading.

The snipe eel grows to 140 cm in length. It is among the biggest deep sea fish. It has a very long beak-like mouth. The mouth has bristles along the edges. For a long time scientists wondered how the snipe eel used these bristles. Finally, they observed the snipe eel feeding. The snipe eel waves its head back and forth in the water. The bristles act like Velcro to snag deep sea shrimp by the antennae.

The bright red Deep Sea Shrimp is only 4 cm long. It seems much longer because of its very long antennae. These antennae may sense different chemicals in the water. The chemicals help the shrimp find food and mates. They may also help it avoid predators. The Deep Sea Shrimp has red photophores on its underside. The photophores countershade the shrimp.

The gulper eel has a very large mouth. It also has a stomach that can stretch. This lets the gulper eel eat prey equal to itself in size. The gulper eel can grow to 76 cm. Most gulper eels are about 40 cm long.

The dull brown tripod fish lives on the ocean floor. The pelvic fins are very long, about half the length of these fish which can grow to 29 cm. The pelvic fins and long tail help the tripod fish skim along the ocean floor. Tripod fish eat tiny animals (zooplankton). Threads on the fins sense the zooplankton in the water when they brush into the fins.

The translucent eelpout is a common deep water fish. It has a very uncommon behavior. When this fish is startled, it rolls up into a donut shape. Scientists wonder how this helps them survive. Some think it makes the eelpout look like a stinging jellyfish. The eelpout grows to 18 cm. It eats any animal it can fit into its mouth.

Many different kinds of siphonophores live in the deep sea. This one can grow to 20 meters in length. A siphonophore is one animal made of many individual animals. Scientists call it a colony. The tentacles act as fishing lures. The lures attract the prey. The tentacles sting it. Then they pull it into one of the mouths.

This 4 cm long jelly can glow (bioluminesce). Its tentacles pulse blue and red. They change color as it swims through the water. When a predator appears, the colobonema increases light output. Then, in an instant, it separates its lighted tentacles. The jelly swims off in a different direction. The predator is left with some stringy tentacles. The jelly is free.

amphipod

blackdragon

bristlemouth

Larvacean

Giant Isopod (Bathynomus gigateus) • The giant isopod can grow to a length of over 16 inches, which makes it one of the largest members of the crustacean family.

Divisions of the Deep-sea Habitat • Mesopelagic: from 200 m to 1000 m, near the margin of the continental shelf. Known as • the disphotic zone because it represents the lower limit of photosynthesis. • Bathypelagic: from 1000 m to 4000 m. Known as the aphotic zone because no surface light • penetrates to these depths. • Abyssopelagic: the pelagic zone below 4, 000 m.

Physical Parameters of the Deep Sea • Describe how the deep-sea environment differs from shallow habitats in terms of light • levels, organic production, temperature, and pressure. • What are the major sources of nutrient input into the deep sea?

Feeding in the Deep Sea • There are two main feeding strategies utilized by deep-sea fishes, each with its own set of • morphological adaptations:

• 1). Opportunistic Carnivory: Food is rare in the deep sea, so many fishes just eat • whatever they can catch, whenever they can catch it. Morphological adaptations may include • expandable stomachs, disconnected pectoral girdle (expands gape), large fangs, • bioluminescent organs, and elongate bodies with posterior fin placement.

• 2). Benthic specialization: When food hits the bottom, it stops. As a result, many • fishes specialize in food resources that can be found on or near the sea floor. Scavengers • dominate, but filter feeders and carnivores are also common. Morphological adaptations • may include well-developed lateral line and olfactory senses, caudal and pectoral fin • modifications, and elongate tapered bodies.

Physiology of Deep-sea Fishes • Metabolism: Cold temperatures and lack of nutrients result in slow metabolic rates. Mesopelagic • fishes are slow and lethargic, which is an energy-saving strategy. Much of the movement is vertical.

Sensory Systems • Vision: In the mesopelagic environment light levels are low, so adaptations to enhance the lightgathering • capabilities of eyes are common, as are bioluminescent organs. The eyes of mesopelagic • fishes may be very large or tubular, and may possess a tapetum lucidum. In the bathypelagic, • abyssopelagic and deep benthic zones light is completely absent. The eyes of fishes in these habitats • may be extremely reduced or lost.

• Olfaction: In the mesopelagic and bathypelagic zones olfaction appears not to be very important. • Olfactory systems are generally not well developed, except in species which find mates by smell. In • contrast, fishes associated with the sea floor tend to have very well developed olfactory organs, • which may be used in foraging and reproduction.

Adaptive Morphology • Organisms that live in the dep sea have to adapt to the various conditions they find there. The shape and structure of the body of deep sea creatures is adapted to those conditions.

Scarce food affects body structure • b/c food is scarce, deep sea fish tend to conserve as much energy as possible. The energy they have must be allocated between growth, maintenance and reproduction.

Deep sea fish lower their energy use by… • having weak muscles • bones that are less dense • lower metabolic rate • slower breathing rate (respiration) • very reduced swim bladder

Adaptations for feeding

• Deep sea fish need to take full advantage of any potential prey they might encounter so they tend to have large mouth, jaws and teeth and highly extendible stomachs so they can handle large prey or carcass.

This fish can extend its stomach up to three times its size swallowing much bigger prey.

Adaptations of the lateral line • The lateral line in fish is used to detect movement around them. It consists of neuromasts, mechanosensory cells with cilia (hairs) that can detect water displacement and therefore movement. Because the upper ocean has currents, the detection system is located in closed or open pits. In the deep sea, fish do not need to worry about strong currents therefore their lateral line is located on the surface or even on stalks.

Body size in deep sea fish • In early studies of demersal deep sea fish, increasing body size was been reported and this became known as the Heincke’s Law. Later studies however appear conflicting with increases or decreases in body size with increasing depth reported. The differing trends between different groups of deep sea fauna may be due to their behavior and ecology.

• scavangers have an increase in body size with depth whereas predators less so or even a decrease in body size with depth

• Visible light made by living creatures is known as bioluminescence. • bioluminescence - the emission of visible light made by living organisms such as the firefly and various fish, fungi, and bacteria.

• the firefly is probably the best recognized example of bioluminescence many organisms in each kingdom exhibit it as well • bacteria, protozoa, fungi, sponges, crustaceans, insects, fish, squid, jellyfish, and lower plants.

On land, bioluminescence is rare. • By contrast, in the oceans, bioluminescence is very, very common. In fact, it would be difficult to find any place in the ocean where bioluminescence doesn't exist.

Flashlight fish • In the mesopelagic zone (200 -1000 m), approximately 90% of all the animals (fish, shrimp, squid, and gelatinous zooplankton) are bioluminescent.

• Light is generated either by the fish itself or from light emitting bacterial cells. Bioluminescence is created from an enzyme called luciferase, which is activated by oxygen (thereby enabling a regulatory control mechanism). It is of interest to note that bioluminescence only occurs in salt water fish as salt is also one of the necessary elements for bioluminescence.

• • The light is produced by symbiotic bacteria within light-emitting cells called photophores. It is produced by a chemical reaction when a substance called a luciferin is oxidized. When the light is released, the luciferin becomes inactive until it is replaced by the animal. Some animals can make luciferin themselves, or it may be synthesised by symbiotic bacteria inside the photophore. The photophores, or light-emitting cells, range from simple clusters of cells to complex organs surrounded by reflectors, lenses, colour filters and muscles. The most common coloured light produced by marine organisms is blue. This is also the colour that penetrates furthest through water.

The vampire squid lives in very deep waters around the world. This small squid has glowing tips on its tentacles. • One of the features of biological light that distinguishes it from other forms of light is that it is cold light. Unlike the light of a candle, a lightbulb, a star or even the glow of heated metals, bioluminescent light is produced with very little heat radiation.

• Were it not for bioluminescence it is probable that most deepsea fish would be blind. Bioluminescense therefore serves a mulitude of functions - increased vision in otherwise lightless environment, attract a mate, seek out or lure prey closer, frighten off potential attackers and most importantly camoflage.

"A flash of light in the ocean is a big deal and all eyes are drawn to it" • Most deep-sea fish have large eyes to gather as much of that light as possible. The crucial feature for capturing photons is the size of the pupil, and for some fish the only way to enlarge the pupil without making the eyes too big to fit in the head is to do away with the outer parts of the eyeball.

• The Flashlight fish of the Red Sea uses bioluminescence to see better in the dark sea environment it inhabits. The light that shines from pockets under its eyes act as headlights for the fish as it swims about.

• Like most bioluminescent fish, it does not produce its own light but instead harbours bioluminescent bacteria. The bacteria living in this pocket under the eye are always producing light, so this fish has a flap of skin like an extra eye lid to cover the lighted pocket when it doesn't want to be seen.

• This symbiotic relationship between fish and bacteria can be used by the fish to help in sight as in the case of this fish, to help keep schools together by making the individual fish easier to see, to make a quick escape from predators by leaving behind a cloud of light, or to hunt.

Attraction of Prey • The Angler fish is an example of a fish that uses its symbiotic bacteria to make hunting easier. The lighted spot on the end of a rod sticking out of the fishes head is used as a lure. When other fish come close to see what the light source is, they are easily snapped up by the angler's jaws.

Interspecies Recognition • Dragonfish have two sets of light organs on their heads. A pair of photophores (light emitting organs) located behind the eye emit blue- green light, like other fish. A second light organ beneath the eye emits light in the red part of the spectrum, which is invisible to other fish.

• Although the red light doesn't travel very far, it allows the Dragonfish to see their prey without alerting the prey or any potentially curious predators; plus it also enables this species to signal each other using the red light and as such it becomes a visual signalling system that is only meant for themselves to see.

Camoflage • In an effort to try and blend into the environment species emit light of a similar wavelength to ambient light levels, thereby disguising the shadowing silhoutte their bodies cause when perceived against an illuminated background. The use of ventral and lateral bioluminescent photophores enables 'countershading' camoflage. • ventral - describes the lower abdominal region of an organism • lateral - is relating to the sides of an organism of structures

• Even in the twilight zone, dimly lit by the last vestiges of sunlight, bioluminescence comes in handy. An animal looking upwards will see the shadowy silhouettes of creatures moving overhead against the dim light above. Some fish and squid make themselves invisible by counterillumination, giving out light of matching intensity from photophores along their bellies.

• The Hatchet Fish live and hide in the down welling sunlight of the Mesopelagic zone (2001000 m) by the use of bioluminescence. The Hatchet Fish has little "holes" or clusters of ventral photophores and the light emitted by these photophores in conjunction with the odd body features eliminate the fishes silhouette thus providing an effective means of evading predators.

Deep-sea cucumber

Snaggletooth

Deep-Sea Lizardfish

Deep-sea glass squid

Fangtooth

This deep sea shrimp, Acanthephyra purpurea, spews bioluminescence to blind or distract a predator.