Lecture 22- reproduction

Question 1

iteroparous:

Answer 1

individuals with more than a single breeding opportunity in a lifetime. this describes most fish

Question 2

semelaparous:

Answer 2

a single “all in” breeding event per lifetime. salmonids are a good example of this.

Question 3

most fish are gonochoristic, meaning their gender is fixed at birth or insemination, these fishes employ three mating stratgies:

Answer 3

1. Promiscuous- no mate choice (anybody will do). often assoicated with breeding shoals 2. Polygamous- multiple partners either polygyny or polyandry. Polygyny occurs when a single male defends a nest or guards a harem of females like the electric yellow fish. polyandry occurs when one female mates with several males like the lake sturgeon. much rarer! 3.) Monogamy: occurs when fishes have one mate at a time but multiple mates over a lifetime as in the kribensis . this is super rare

Question 4

hermaphorditic fishes are able to switch between male and female or are born both! these are two types of hermaphrodites in fishes:

Answer 4

1.) simultaneous hermphrodites- functionally male and female at the same time ex.) moray eel 2.) sequential: either first male then female or vice versa.

Question 5

what are the two kinds of sequantial and examples?

Answer 5

protoandrous: size in males is not related to fecundity, be female size is so wait until your big to be a female! ex.) clown fish Protogynous: when you are at your largest you are better able to claim and defend a territory so be a female when you are small and do not need to defend a territory then switch to male when you are large enough

Question 6

define parthenogenisis and describe two types

Answer 6

are always female and are able to reproduce in the absences of a mate. 1.) Gynogensis is found in triploid species (3N). these fish need sperm to initiate fertilization but each egg does not need sperm 2.) hybridogensis can produce all female offspring without male input. these fish are often able to reproduce with a mate as well.

Question 7

viviparous:

Answer 7

internal fertilization usually followed by live birth. uncommon 10-15%. almost all sharks are. some sharks get unique with this and insteaf of live birth sharks lay a mermaids purse containng the pup and yolk sac and the purse is attached to plants or other stable structures

Question 8

Oviparous:

Answer 8

external fertilization followed by varying amounts of parental care.

Question 9

what is a common problem with external fertilization?

Answer 9

ensuring that the male you have chosen fertilizes the eggs and for the male ensuring only you fertilize eggs. this is seen in jack salmon which are immature males stealing eggs from mature males

Question 10

site selection for spawning can be veru specific and often is based on what?

Answer 10

a suite of physical characteristics like rock size, water velocity etc.

Question 11

what fish has a very unique and beautiful constructed nest?

Answer 11

puffer fish

Question 12

how do tuna spawn that is different then the puffer fish?

Answer 12

occurs in open water with no nest or specific site selection

Question 13

most often the —– cares for the young

Answer 13

male

Question 14

Fill out this tree

Answer 14