Lab #5 Group Characters

Question 1

Acanthopterygii Characters

Answer 1

These are the ray finned fishes
Shared Traits Include

Development of ascending process of the premaxilla (improve upper jaw mobility). Slides along rostral cartilage

Highest development of pharyngeal teeth

Ctenoid scales: better protection (parasites)

Physoclistous swim bladder

2 Distinct dorsal fins: 1st is spiny, 2nd is soft

Pelvic and anal fins with spines

Thoracic-positioned pelvic fins

Pectoral fins placed laterally rather than vertically (reduce drag)

External symmetry of caudal fin: hypural plate

Question 2

Order Beloniformes

Answer 2

Needlefishes, flying fishes, halfbeaks
Long and slender, pointed snouts or beaks
Dorsal and anal fins set far back on body
Lower lobe of caudal fin is longer, provide thrust when out of water
Soft rayed spineless fins

Question 3

Order Cyprinidontiformes

Answer 3

Guppies, four-eyed fishes, pupfishes
Largely freshwater, tolerance to high salinity
Surface insect feeders (upturned mouth)
Hermaphroditism (self-fertilization) or parthenogenesis
Strong sexual dimorphism
Scales on head, no lateral line (differ from minnows this way)

Question 4

Order Gasterosteiformes

Answer 4

Sticklebacks, tubesnouts
Body armour plates and small mouths
Pelvic girdle is never attached to cleithrum (shoulder girdle)
Supramaxillary, orbitosphenoid and basisphenoid skull bones are absent (more room for eyes)
Tube like mouth, pipette feeding
Brooders of eggs, nest builders, eggs guarded by males

Question 5

Families in Gasterosteiformes

Answer 5

Gasterosteidae
Aulorhynchidae

Question 6

Families in Scorpaeniformes

Answer 6

Scorpaenidae
Hexagrammidae
Cottidae
Hemitripteridae
Psychrolutidae
Anoplopomatidae
Rhamphocottidae

Question 7

Order Syngnathiformes/Family Syngnathidae

Answer 7

Pipefishes, seahorses
long, thin cylindrical fishes, with bony rings encircling the body
Tube-like snout and binocular vision
Pelvic fins absent
Pipefish propel with tail, sea horse use dorsal and pectoral
Modified caudal peduncle for holding stems
Male brood pouch

Question 8

Order Scorpaeniformes

Answer 8

Suborbital stay – posteriorly directed spine from suborbital bone
Rounded pectoral fin, with deeply indented rays in the membrane
Caudal fin usually rounded
Thoracic pelvic fins have 1 spine and 5 soft rays

Question 9

Family Scorpaenidae

Answer 9

Rockfishes, scorpionfish
Moderately large mouth and terminal
Gill membranes separate from isthmus
7 branchiostegal rays
2 opercular and 5 preopercular spines
2 closely adjacent dorsal fins with 11-17 spines in first 8-18 soft rays in second
Anal fin has 3 strong spines and 5-9 rays
Fine spines have toxin gland at base for defense

Question 10

Family Hexagramidae

Answer 10

Greelings, lingcod
6 branchiostegal rays
2 dorsal fins elongate and either close together or blend into each other
Gill membranes joined to isthmus
Teeth small, canniform in lingcod
Some have multiple lateral lines
Boldly striped or blotchy colouration
Mostly shallow water marine fishes

Question 11

Family Anoplopomatidae

Answer 11

Sablefishes
Head without spines ridges or cirri
2 dorsal fins elongate and separate
2 well developed nostrils, gill membranes attached to isthmus
Single lateral line
Body colour is brackish or green
Small scales weakly ctenoid

Question 12

Family Rhamphocottidae

Answer 12

Grunt sculpin
Head very large, about half the standard length
2 rounded ridges, extending along top of the head from snout to nape. Each terminating in a stout, blunt spine
Mouth terminal, small, directed forward as a long snout.
Spines on dorsal fin weak, and recessible within a groove.
Rounded caudal fin
Lower eight pectoral rays thickened to support fish on substrate. Swims weakly with head
held high over rocks and seaweed, supported on long pectoral rays

Question 13

Family Cottidae

Answer 13

Cottid sculpins
Largest family of BC marine fishes
Most are stout-bodied and tapering towards tail, with narrow caudal peduncles.
Large heads, with eyes tending to be nearer top of head than sides.
Scale distribution highly variable: covering body, in rows, or absent except along lateral line.
Most species have numerous small fleshy appendages, cirri that may have a sensory or camouflage function
No spines in anal fin
Pectoral fins expanded and fanlike.
Pelvic fins small, thoracic.

Question 14

Family Hemitripteridae

Answer 14

Sailfin sculpin
Nocturnal
Reduced ctenoid scales in the form of minute spines embedded in papillae covering the body
Basihyal absent (structure that is superficially similar to a tongue)
Six branchiostegal rays
Long dorsal fin rays made of spiny rays anteriorly followed by a deep notch
Lower jaw and top of head have fleshy cirri
Rounded caudal fin

Question 15

Family Psychrolutdae

Answer 15

Fathead sculpins
Range in depth from inshore shallow water to
offshore, 2800 m

Body naked or with plates bearing prickles
* Interorbital space usually greater than exposed eye diameter, lateral line is reduced

• Pelvic fin with one spine and three soft rays, dorsal fins are usually continuous, often partially hidden by the skin
• System of well-developed bony arches which may bear spines
• Rounded caudal fin.
• Lower eight pectoral rays thickened to support fish on substrate. Swims weakly with head held high over rocks and seaweed, supported on long pectoral rays

Question 16

Family Gasterosteidae

Answer 16

sticklebacks

3-16 isolated spines preceding dorsal fin.

• Large eyes.
• Small, upturned mouth and narrow caudal peduncle.
• Voracious feeders on various kinds of worms, small
  crustaceans, aquatic insects and larvae, eggs
  and fry of other fish, including their own species.
• Variable number of bony plates on sides replace scales.

Question 17

Family AULORHYNCHIDAE

Answer 17

tubesnouts

Heads greatly prolonged into slender snout with small mouth and hinged upper jaw.

• Dorsal fin placed well back on body, opposite anal fin, and preceded by about 25 isolated
  spines.
• Body partly covered by rows of distinct bony plates