Excretory Reproductive Anatomy Excretory Reproductive Close anatomical ties

Excretory & Reproductive Anatomy

Excretory & Reproductive - Close anatomical ties w Typical vertebrate arrangement w Excretory and reproductive anatomy closely tied w May share common ductwork in some individuals

Excretory/Reproductive Systems

General locations

Kidneys

Excretory/Reproductive Systems w Systems lie in close proximity to one another within body cavity

Excretory System w Pronephros functional in adult hagfish, fish embryos

Excretory System w Mesonephros portion of functional kidney in adult fish

Typical connections with circulatory system

Fish kidneys w Diffuse organs on either side of vertebral column w Varying degree of connection with reproductive system w Little connection in most advanced fishes

Shark kidney w Sharks and relatives have close ties between kidneys and testes w Share ductwork

Kidneys and urinary bladder w Some fish have a urinary bladder w Located at end of ureter(s) w More often present in male fish

Hagfishes w Monoecious - all individuals have capacity to be either male or female w Single gonad can develop into testis or ovary w Can it switch or be both at same time?

Hagfish ovary w Produces few, large eggs w 1 or 2, or up to 30, depending on species

Hagfish ovary w Eggs get dumped into body cavity before exiting body w Internal/self fertilization?

Lamprey ovary or testis w Lampreys are male or female w Single ovary or testis w Reproductive products dumped into body cavity before exiting (no ductwork)

Class Chondrichthyes w Sexes separate and fertilization internal w Oviparous, ovoviviparous, viviparous

Shark testes w Paired testes w Located near anterior end of body cavity

Testes with ducts

Ductwork w Ducts convey sperm to storage area w Stored until copulation

Female sharks

External sex characteristics w Pelvic claspers in males w Aid in sperm transfer to female w Female with simple cloacal opening

Other characteristics w Male sharks, chimaeras may have head clasper as well as pelvic clasper w Not used in sperm transfer

Bony fishes-paired gonads

Bony fishes w Most bony fish are dioecious (male and female) w Gender differences not always very apparent w Tubercles may develop in males

Breeding or nuptial tubercles

Bony fishes w Others may develop vivid colors w Males boldly marked w Many minnows, darters

Bony fishes w Fertilization is usually external (oviparous) w Female ejects eggs, male ejects sperm (milt)