L8_9_10_reproduction_11COLOR

L8_9_10_reproduction_11COLOR - REPRODUCTION AND DEVELOPMENT...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
REPRODUCTION AND DEVELOPMENT (outline table 21.1 , textbook)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
I) Number of breeding opportunities Semelparous: spawn once in a lifetime, then die; most are diadromous or have a major migration in their life cycle e.g., Pacific salmon, lampreys, river eels Iteroparous: multiple spawns in a lifetime Daily – many tropical fishes Monthly/tidally – other tropical fishes Seasonally – nearly all temperate fishes
Background image of page 2
Salmon, Oncorhynchus tshawytscha , die after reproducing once: semelparity
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Most fishes spawn many times over the course of their lives: iteroparity
Background image of page 4
II) Mating system Basis for mating systems is anisogamy – difference between egg and sperm sizes; leads to differences in how males and females maximize Reproductive Success (RS): Females : maximize resource intake, convert this to eggs Males : maximize matings; high potential mating success, leads to competition e.g. Bluehead wrasse Female RS ranges between 2,000 - 15,000 young/day Male RS ranges between 0 (most males) and 1,500,000 young/day!
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
II) Mating system Promiscuity: multiple partners for males and females, (also known as polygamy ) Polygyny: multiple females for one male in fishes, this is often serial, one female after another e.g. bluehead wrasse, dominant male can mate with up to 150 females each day Polyandry: multiple males for one female in fishes, this is most often simultaneous (group spawning) e.g. in bluehead group spawns, each female mates with 3 - 10 males simultaneously Monogamy: partners remain together for extended period of time These mating systems can be reflected in the gender system, or pattern of sexual expression – sex change, etc.
Background image of page 6
Oxymonacanthus halli, monogamous, pair for life
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
III) Gender systems Gonochorism: one sexual tissue type per individual Hermaphroditism: an individual that has both ovarian and testicular tissue in a lifetime - Simultaneous: both gonadal tissues functional in one individual - Sequential: a switch from one gonadal tissue to another. (Sex change evolved in 23 families, 7 teleostean orders) Protogynous: female ! male Protandrous: male ! female
Background image of page 8
Simultaneous hermaphroditism: both gonadal tissues functional in one individual Advantages: - mate with whomever you meet - can nearly double reproductive output Many deep-sea families, some gobies, some serranids Scopelarchus - rapid switches of sexual function How is cheating avoided?
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Hamlets, (Serranidae) simultaneous hermaphrodites Male-female role switching, during spawning (or egg trading) – prevents “male cheating”
Background image of page 10
Sequential hermaphroditism: a switch from one gonadal tissue to another Protogynous : female first e.g., seabasses, damselfishes, wrasses, parrotfishes, gobies, angelfishes, cichlids, swamp eels Protandrous : male first e.g., anemonefishes, flatheads, some eels More common in nearshore tropical and subtropical marine systems Cool temperate and FW exist but less common Most members of a family will be either protogynous or protandrous
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
CA sheephead, protogynous sex changer, all individuals
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 74

L8_9_10_reproduction_11COLOR - REPRODUCTION AND DEVELOPMENT...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online