Excretory & Reproductive
Anatomy
Excretory & Reproductive
- Close anatomical ties
 Typical vertebrate
arrangement
 Excretory and
reproductive
anatomy closely tied
 May share common
ductwork in some
individuals
Excretory/Reproductive
Systems
General locations
Kidneys
Excretory/Reproductive
Systems
 Systems lie in close
proximity to one
another within body
cavity
Excretory System
 Pronephros functional in adult
hagfish, fish
embryos
Excretory System
 Mesonephros portion of functional
kidney in adult fish
Typical connections with
circulatory system
Fish kidneys
 Diffuse organs on
either side of
vertebral column
 Varying degree of
connection with
reproductive system
 Little connection in
most advanced
fishes
Shark kidney
 Sharks and relatives
have close ties
between kidneys
and testes
 Share ductwork
Kidneys and urinary bladder
 Some fish have a urinary bladder
 Located at end of ureter(s)
 More often present in male fish
Hagfishes
 Monoecious - all individuals have capacity to be either
male or female
 Single gonad can develop into testis or ovary
 Can it switch or be both at same time?
Hagfish ovary
 Produces few, large eggs
 1 or 2, or up to 30, depending on species
Hagfish ovary
 Eggs get dumped
into body cavity
before exiting body
 Internal/self
fertilization?
Lamprey ovary or testis
 Lampreys are male
or female
 Single ovary or testis
 Reproductive
products dumped
into body cavity
before exiting (no
ductwork)
Class Chondrichthyes
 Sexes separate and
fertilization internal
 Oviparous,
ovoviviparous,
viviparous
Shark testes
 Paired testes
 Located near
anterior end of body
cavity
Testes with ducts
Ductwork
 Ducts convey sperm to storage area
 Stored until copulation
Female sharks
External sex characteristics
 Pelvic claspers in
males
 Aid in sperm
transfer to female
 Female with simple
cloacal opening
Other characteristics
 Male sharks,
chimaeras may have
head clasper as well
as well as pelvic
clasper
 Not used in sperm
transfer
Bony fishes-paired gonads
Bony fishes
 Most bony fish are
dioecious (male and
female)
 Gender differences
not always very
apparent
 Tubercles may
develop in males
Breeding or nuptial tubercles
Bony fishes
 Others may develop vivid colors
 Males boldly marked
 Many minnows, darters
Bony fishes
 Fertilization is usually external (oviparous)
 Female ejects eggs, male ejects sperm (milt)