Lab #7 Intro

Question 1

Family Pholidae

Answer 1

Gunnels

feed on small crustaceans and molluscs. There
are about 14 species; six are found in British Columbia

Dorsal and anal fins are always confluent with caudal fin

Dorsal fin consists entirely of spines and is usually at least twice as long as the anal fin

Body elongate, compressed

• Dorsal fin long, contains only flexible spines
• Distance from snout to anal origin greater than half of body length
• Pelvics very tiny or absent.
• Five or six branchiostegal rays.
• Pyloric caeca absent.
• Ribs absent.
• Abdominal vertebrae with parapophyses united, forming hemal arches.
• 80-105 vertebrae

Question 2

Family ANARHICHADIDAE

Answer 2

Wolf eels

rocky crevices of the north Pacific and Atlantic

Dorsal fin long, starting at the head, and composed of 69-88 flexible spines in Anarhichas and 218-250 in Anarrhichthys.

• Anal fin with 42-55 soft rays in Anarhichas and 0-1 spine and 180-233 soft rays in Anarrhichthys.
• Caudal fin separated from dorsal and anal fins by a short peduncle in Anarhichas, median fins confluent and tapering to a point in Anarrhichthys.
• Pectoral fins large and rounded, with 18-24 rays.
• Pelvic fins absent.
• One pair of nostrils.
• Scales cycloid, minute and non-overlapping, or absent
• Most species have strong canines and molars for digging out and crushing clams and other hard-shelled prey. Gill membranes attached to the isthmus, gill openings widely separated.
• Branchiostegal rays: 6-8.
• Swim bladder absent.
• Vertebrae 72-89 to 251.
• Primarily demersal, inhabiting shallow to moderately deep cold waters

Question 3

Family DACTYLOPTERIDAE

Answer 3

Flying gunnards

walking’ movement on the sea floor,

Head large and blunt, with the bones forming a helmet.

• Keels and a long preopercle spine.
• Scales scute-like.
• Pectoral fins greatly enlarged, the inner rays free; total 28-37 rays.
• Two isolated dorsal spines preceeding the two dorsal fins.
• Thoracic pelvic fins; with one spine and four soft rays.
• Lateral line absent.
• Vertebrae 22. Reaches about 50 cm maximum length

Question 4

Family NOTOTHENIIDAE

Answer 4

codfish ice

depth-related diversification, such as
increased fatty tissues and reduced mineralization of the bones

spleen may be used to remove ice crystals from circulating blood

antifreeze glycoproteins in their blood

Body scaled with gill membranes forming a fold across the isthmus.

• Mouth protractile.
• First dorsal fin is spinous with 3-11 spines, the second dorsal with 25-42 soft rays.
• One to three lateral lines

Question 5

Family AMMODYTIDAE

Answer 5

Sandlances

elongate, metallic blue or green fishes up to 20 cm long

Lateral line high on back, fold of skin along each side of belly.

• Caudal fin forked; pelvic fins absent.
• Lower jaw projects, snout pointed.
• Scales small, cycloid.
• Lack swim bladder

Question 6

Family BLENNIDAE

Answer 6

Combtooth blennies

slender, elongate body and cryptic colouring

distinctive teeth, which are close-set in a single row on each jaw

Most blennies feed on algae and small invertebrates, but some attack other fish to steal bites of fin, scales, or skin.

males are larger than females and, in some species, have a larger head

Blennies have scaleless, elongated bodies, and comb-like, slender, close-set teeth, which can be either fixed or movable.

• A pair of giant canines give the saber-toothed blennies their name, and in the poison- fanged blennies (Meiacanthus) these teeth are hollow and contain an injectable toxin.
• In blennies the palatines are toothless, and the mouth not protractile.
• The head is often blunt and typically adorned with tentacles or cirri.
• Blennies are usually small, but a few can reach 55 cm.
• The dorsal fin has more rays than spines, and the anal fin has two spines.
• Blennies exhibit a wide variety of uniform colours as well as spots, stripes, or bands, and some species exhibit two or three colour patterns.
• Cryptic colouring is widespread.

Question 7

Family G OBIESOCIDAE

Answer 7

Cling fishes

small, tadpole-like fishes, mostly marine but with many freshwater species

Found in shallow water adhering to rocks, shells, eelgrass, or hiding under rock recesses.

No swim bladder, as is true for many benthic fishes.

• No scales.
• No spines, probably a derived feature in which they have secondarily been lost.
• Dorsal and anal fins set back far on trunk, more than past halfway along the length

Question 8

Family GOBIIDAE

Answer 8

Gobies, mudskipper

Usually small, benthic, or sand-burrowing fishes of sedentary habit. Mostly marine, but there are
many freshwater species

among the largest family of marine fishes, at least equal in number to the cyprinids and cichlids

pelvic fins united, and form a flaring conical suction device in many

amphibious mudskippers, whose pectoral fin bases
are muscular, and enable the fish to climb out of the water

feed on aerial insects – breathe while out of the water by means of a mass of blood vessels in the roof
of the mouth

Small gill openings.

• Rounded tail.
• Usually no swim bladder

Question 9

Family ACANTHURIDAE

Answer 9

Surgeonfishes

medium-sized compressed fishes with small mouths that usually form shoals
over coral reefs – herbivorous

scalpel-like spines (modified scales) on the
caudal peduncle

Deep-bodied, moderately-sized fishes, popular with marine aquarists.

• Extremely compressed.
• Beaklike snout with small mouth.
• Incisor-like teeth

Question 10

Family ZANCLIDAE

Answer 10

Moorish idol

Coal reef fish

adult has an extended snout that is well suited for
foraging on invertebrates and algae in small crevice

deep-bodied with strong lateral compression

Moorish idols reach a maximum length of 23 cm (about 9 inches), but are often smaller.

• Idols have a highly compressed (flat) body that is shaped like a disc.
• They have sharply contrasted vertical bands of white, yellow, and black.
• Besides the colour (which is shared by a few butterflyfish), the snout and dorsal fin are the defining characteristics of a Moorish idol. The snout is shaped like a tube, with a tiny mouth on the end.
• The dorsal fin is long and extends backwards, narrowing into a trailing extension with a distinctive white colour

Question 11

Family SPHYRAENIDAE

Answer 11

Pacific Barracuda

Fish spawn in shallow waters such as estuaries

eggs drift out into the ocean and eventually develop

large gape and large teeth that allow them to feed
on very large fish by chopping them in half

They are a grayish brown above and silvery below, which is quite universal throughout their geographic range. They often have dark ink-like spots arranged without a pattern on their sides. The young have dark crossbars on their backs and blotches on their sides.

• Two widely separated dorsal fins.
• They have large scales and a pointed head with a large mouth and long knife-like caniform teeth.
• They can reach up to 2 meters in length.
• Lower jaw projecting, which is helpful in biting.
• The young also have a soft dorsal fin and the anal and caudal fins can be blackish

Question 12

Family SCOMBRIDAE

Answer 12

Tuna, Mackerels

Extreme streamlining with spindle or cylinder shape in cross section.

• Smooth skin with small cycloid scales.
• Countershading colouration: iridescent blue or green above and silver or white below.
• First dorsal fin can be depressed into a shallow groove while fish is swimming rapidly.
• Small second dorsal and anal fins opposite each other.
• Rows of small finlets from second dorsal fin to caudal fin.
• Caudal fin tall and lunate, having a high aspect ratio.
• Tendons run from trunk musculature to tail, passing over lateral keels of caudal peduncle.
• Swim bladder reduced or absen

Question 13

Family XIPHIIDAE

Answer 13

Bilifishes, swordfishes, Marlins, sailfishes

large, solitary predators

First dorsal fin in mature fishes is soft-rayed, tall, sickle-shaped, and permanently erect.

• The first dorsal fin is especially long and high in sailfishes and can be retracted into a groove during rapid swimming, unlike that of the swordfish, which is always erect.
• Very small second dorsal fin lies opposite a similarly reduced second anal fin near the tail.
• Lack scales, teeth.
• Pelvic fins reduced or absent

Question 14

Family CHANNIDAE

Answer 14

Snakeheads

freshwater perciformes that somewhat resemble a bowfin

Africa and Asia but have become invasive in North America

long dorsal fins and large mouths, and rely on quickly
striking at fish that swim too close to these veracious predators

short treks onto land using a lung-like organ

Elongate, torpedo shaped body.

• Long dorsal and anal fins.
• Rounded caudal fin.
• Pelvic fins in line with pectoral fins (help to distinguish from bowfin).
• Suprabranchial organ (modified lung like organ) to breathe on land.
• Small, flattened head with large mouth.
• Long tubular nares.
• Eyes on top of head.
• Modified scales on head resemble those of a snake.
• Large cycloid and ctenoid scales on body

Question 15

Order PLEURONECTIFORMES

Answer 15

Soles, flounders, halibut

Highly compressed body (hence, the common name flatfishes).

• Single, long dorsal and anal fins with flexible spines. The anal fin often has a stiff spine at its anterior.
• Pelvic fins small and thoracic or jugular in position. Caudal fin square-cut, rounded, or slightly forked.
• Swim bladder absent, body cavity small and confined to region between pectoral fins and anterior part of anal fin.
• Scales small and usually ctenoid on the eyed side, cycloid on the underside

Question 16

Family PLEURONECTIDAE

Answer 16

Right eye flounders and sole

Mostly in colder seas, but a few are tropical, or brackish and fresh water in habitat

Both eyes are usually on the right side (dextral), except in the starry flounde

The lateral line often has a dorsal branch that runs along the base of the dorsal fin

1. Shape of caudal fin; rounded in this example, as opposed to straight or lunate or forked.
2. Lateral line strongly arched over pectoral fin as shown here, as opposed to being straight or slightly arched.
3. Accessory lateral line canals – length and position relative to dorsal fin and operculum.
4. Both eyes on right side (as shown here), or left side.
5. Posterior end of maxilla does not reach to pupil of eye as shown here.
6. Spine preceding anal fin.
7. Pectoral fin shorter than head length (tip of snout to posterior most edge of operculum)

Question 17

Family BOTHIDAE

Answer 17

Left-eye flounder

Single, unbranched lateral line.

• Eyes are further apart in males of some species, and pectoral fins are sometimes longer.
• Pelvic fin base on eyed side longer than on the blind side.
• Dorsal and anal fin rays shortened posteriorly.
• Anus generally far up on blind side

Question 18

Family PARALICHTHYIDAE

Answer 18

Sound flounder

Marine, present in all oceans, rarely in fresh water

Eye migration right to left

Grow to about 40 cm long; those most commonly seen are about 15-20 cm.

Body flat but typical fish-shaped

head is large with bulbous eyes, both on the left side

tail fin is well separated from the dorsal and anal fins

large caniniform teeth.

Typically have a bony ridge between their eyes

Has a fully developed lateral line on the blind side as well as the eyed side.

The eyed side is usually speckled with spots of various sizes and patterns to match the colour of sandy habitat

Question 19

Order TETRAODONTIFORMES

Answer 19

most derived orders of all teleost

often-bizarre appearance reflects great departure from the basic fusiform shape of almost any other group of fishes

Reduced number of bones in skull due to high degree of fusion; skull is thus of a solid construction.

• Lack lower ribs, so the body is less flexible than in most teleosts. The skin is tough and leathery, forming a rigid enclosure for the body organs.
• Propulsion is never by body undulation due to the rigid body. Propulsion is by rapid movement of the rounded caudal fin, pectoral fins, or by posteriorly located dorsal and anal fins. In spite of being slow swimmers, they are highly maneuverable amongst coral reefs.
• Most have some form of protection including inflatable bodies and toxic internal organs (pufferfishes); spine-covered bodies (porcupinefishes); thick skins (molas), or rigid boxlike armour (boxfishes, trunkfishes, and cowfishes).
• Small gill openings, usually as holes anterior to pectoral fins.
• Premaxillae and maxillae fused together, stout teeth, or toothlike beaks.
• Large pharyngeal teeth that act as secondary crushing devices for further mechanical breakdown of food

Question 20

Family BALISTIDAE

Answer 20

Triggerfishes

relatively slow-moving, solitary reef dweller

Laterally compressed body.

• Three dorsal spines, the first of which is stout and erectile. It can be locked into position by the second dorsal spine (the trigger). This, together with extension of a pelvic spine, enables the fish to lodge itself into crevices from which it cannot easily be dislodged by a
  predator.
• Some species defeat the spiny defense of a sea urchin by blowing a stream of water at it to overturn it, exposing its less protective underside to attack.
• Tiny mouths. Upper jaw usually with four teeth in outer and three in inner series on each premaxillary, developed for crushing rather than nibbling coral polyps.
• Pelvic fins absent.
• Scales plate-like, in a regular series on sides of body

Question 21

Family MONOCANTHIDAE

Answer 21

Filefishes

Similar in appearance to triggerfishes but lack the trigger mechanism

small mouth with three teeth in outer series, two in inner series on the premaxillary, forming a rasp or file for feeding on hard corals.

Usually two dorsal spines, the second usually much smaller or absent.

• Soft dorsal, anal, and pectoral rays simple.
• Scales small in regular series.
• Body prickly or furry to touch.
• Upper jaw usually with three teeth in outer and two in the inner series on each
  premaxillary.
• 19-31 vertebrae.

Question 22

Family OSTRACIDAE

Answer 22

Boxfishes, trunkfishes, cowfishes

entire body, except the fins and caudal peduncle, being encased in a protective covering of enlarged, thickened, and sutured scale plates

Triangular or rectangular in cross section, providing stability when hovering.

• Stout spines may occur above the eyes and project anteriorly as hornlike extensions (e.g. ‘cowfish’).
• Dorsal and anal fins used for propulsion.
• Feed mainly on coral polyps

Question 23

Family DIODONTIDAE

Answer 23

Porcupinefishes

porcupinefishes have more prickly skins
than pufferfishes

the spines are much stronger and larger than those of pufferfishes, and the tooth plates are fused into a single piece in the upper and lower jaws

Question 24

Family TETRAODONTIDAE

Answer 24

Pufferfishes

strong beaklike teeth formed by fusion of outer bones of the jaws, four in pufferfishes (hence, the tetra- prefix)

beak is subdivided by surface sutures, giving it the false appearance of having separate teeth.

toxin of the pufferfish (called tetrodotoxin) is mostly in the gonads and other viscera. It is a potent neurotoxin that causes paralysis

smallest known genome of any vertebrate

Question 25

Family MOLIDAE

Answer 25

Ocean sunfishes

They are the largest species of bony fish

occur in tropical and temperate seas, usually far offshore

Molas feed on jellyfish, salps (pelagic tunicates),
ctenophores, and occasionally, small crustaceans and fishes

compressed and discoid body shape is adapted for passive drifting near the surface on ocean
currents

most prolific of all vertebrates, the female producing up to 300 million eggs

Lack caudal peduncle or fin, giving them a ‘chopped end’ appearance. Instead have a clavus, which is formed by extensions of the dorsal and anal fin rays. The clavus is
broadly rounded and has low, rounded projections (ossicles), which make up the margin.

• The teeth in each jaw are fused to form a plate, and the mouth is small in comparison to the body size.
• Short-based, long, stiffly held dorsal and anal fins set far back on body.
• Large, secondarily cartilaginous skeleton, thick skin covered in rough protuberance