Lecture 2 External Morphology

Question 1

mouth morphology (5) (name, feeding, location)

Answer 1

A. Inferior: Barbels and mandibles are used to sense prey at the bottom of habitat (bottom feeder)
B. Subterminal: rostrum (nose) extends beyond the mouth (same as A = Bottom feeder) also able to eat things higher up in the water column
C: Terminal: mouth opens right at end of snout so they can grab things as they swim by
D: superior: lives close to the bottom as an ambush predator. Mouth facing upward allows ease of capture of prey above
E: Lamprey teeth and plates made of keratin to rasp hole in prey and suck out fluids

Question 2

Body Forms (8) (name, shape, example)

Answer 2

A: Fusiform (tuna) - hydrodynamically efficient body shape
B: Compressiform (butterfly fish) - lateral (left/right) compression
C: Depressiform (rays) - ventral/dorsal compression
D: anguilliform (eels) - round cross section with long body and dorsal fin
E: Filifrom (ribbon eel) - smaller version of anguilliform
F: taenifrom (oarfish) - laterally compressed anguilliform
G: sagittifrom (barracuda) - arrow-like
H. Golbiform (Pufferfish) - globby boi big circle go float float

Question 3

Spiny-Rayed fins

Answer 3

1. Dorsal fin in 2 parts, spiny(anterior) and soft (posterior)

Question 4

Label external morphology diagram

Answer 4

A. head
B. Trunk
C. Tail
D. Caudal Peduncle
E. Lateral line
F. Operculum
G. Preopercle
H. Cheek
I. Interorbital
J. Snout
K. lachrymal Area
L. Chin
M. Barbal
N. Branchiostegal Membrane
O. Branchiostegal Rays
P. Pectoral Fin
Q. Pelvic fin
R. Anal Fin
S. Dorsal Fin
T. Caudal Fin

Question 5

Label Pelvic Fin types

Answer 5

A. Abdominal
B. Subabdominal
C. Thoracic
D. Jugular

Question 6

Label Caudal Fin types and function

Answer 6

A. Rounded - lots of area to push against water = lots of power and drag
B. Truncate - intermediate between rounded and lunate, favoring rounded
C. Emarginate - intermediate between rounded and lunate
D. Forked - Intermediate between rounded and lunar, favoring lunar
E. Lunate - Maximum power with minimal Drag (sailfish)
F. Heterocercal - asymmetrical lunate form
G. Abbreviate Heterocercal - asymmetrical rounded form
H. Homocercal - Appears symmetrical on outside, is asymmetrical inside
I. Isocercal - Appears symmetrical on outside, is asymmetrical inside - fused to vertebrae

Question 7

soft rayed fins

Answer 7

soft dorsal fin, adipose fin sits just above the caudal peduncle