life history strategies and reproductive patterns Flashcards
3 points on iteroparity
- high possibility of adult post spawn survival
- highly variable fry survival
- low reproductive investment by the parents. low fercundity
3 points of semelparity
- low adult post spawn survival (think steelhead, thompson river)
- reliable fry survival
- large energy investment in gametes
what are the three characteristics of the envolved fish for Balon’s Classification?
- early development of form and function
- preferred spawning ground and substrate
- adult reproductive behavior. spawning and incubation
what was the title of the journal entry that balon wrote.
reproductive guilds in fishes. a proposal and definition
who discovered halon?
Axelrod
what are the 3 categories of reproductive guilds?
- non-guarders
- guarders
- bearers
2 types of non-guarders, and some examples of each
Open substrate non-guarders -Pelagophils -Lithopelagophils -Lithophils Brood hiders -Lithophils -Ostracophils -xerophils
2 types of Guarders, some examples
Substrate choosers -lithophils -phytophils -aerophils Nest Builders -Lithophils -Phytophils -Aphrophils
2 types of bearers, examples
External -transfer brooders -forehead brooders -mouth brooders Internal -ovi-viviparous -Ovoviviparous
Pelagophils
scatter adhesive eggs in open water
Lithopelagophils
scatter adhesive or negatively buoyant eggs over rocks and gravel
Lithophils
scatter non adhesive eggs over rocks
Phytolithophils
prefer to spawn on plants, but also use rocks
Phytophils
deposit adhesive eggs onto plants
Psammophils
scatter adhesive eggs on sand and fine roots
Spelephils
hide non-adhesive eggs in stones and caves
Ostracophils
lay eggs in gill chambers of bivalves and ascidians
Aero-psammophils
bury eggs in sand and high tide on beaches
xerophils
adapted to ponds that dry out during the dry season, eggs survive in mud
Polyphils
not preference in nest material
Ariadnophiles
use kidney secretions to glue plants
Actinariophils
nest under anemones
transfer brooders
fish spawn and carry egg to nest site
forehead brooders
males carry eggs on forehead. males pick em up from females vent
mouth brooders
one or both sexes brood
gill chamber brooder
adults can eat while brooding eggs.
skin brooders
males or females carry fry on skin
pouch brooders
male has brood pouch and incubates both eggs and fry
ovi-oviviparous
internal fertilization, eggs deposited. fry get all nutrition from yolk.
ovoviviparous
internal fertilization and incubation
-larvae released as button up
viviparous
-internal fertilization, fry released button-up
Tilapia:
- what is their general diet?
- what family are they a part of?
- how many genera, what are they?
- vegetarian
- cichlidae
- oreochromis
- sartherodon
- tilapia
what are the reproductive guilds for
- tilapia
- sartherodon
- oreochromis
T: nest building lithophores
S: nuclear family mouth brooders
O: arena spawning mouth brooders
Tilapia: reproduction and development
- parents form a pair bond - monogamous for 1+ spawnings
- adhesive eggs in sand nest
- male guards territory and female guards and fans eggs
- parent move fry to secondary nests
- fry leave in 2-3 weeks
- little sexual dimorphism
Sartherodon: reproduction and development
- parents form weak pair bond
- deposit non-adhesive eggs in sand nest. male fertilizes
- one or both parents pick up eggs and incubate them
- some sexual dimorphism
- fry emerge from mouth at button up and return to mouth at night or when there is a threat.
- fry stay with parents 2-3 weeks
Oreochromis: reproduction and development
- arena spawners
- male build nest and guard- female school
- female attracts male, spawns, he fertilizes and picks up and leaves
- female goes to nursery area or back to female school
- emerge at button up and stay with female 2-3 weeks
egg size and spawn numbers of:
Tilapia
Sartherodon
Orechromis
T: 1.2-2mm 1000-6000
Sartherodon 2.4-3mm 100-5000
Oreochromis: 2.8-5mm 25-3000
What do T, S and O feed primarily on?
T: macrophytes
S+O: Phytoplankton feeders also zooplankton
pick algae off plants
filamentous algae
how small are Tilapia’s guts?
5-10x body length. small stomach
Oreochromis: what spp. cultured?
- niloticus: nile tilapia
- mossambicus: egyptian mouthbrooder
- aurea: blue tilapia
- urolepis hornorum: hornorum
history of tilapia culture (old history)
- since 2500bc
- cultured by the romans
- st. peters fish
- biggest culture volume next to carp
- CHINA IS WORLDS LARGEST PRODUCER OF TILAPIA
how to control reproduction of tilapia?
- monosex culture
- early cropping of single year class
- predator stocking
- cage culture
6 methods of monosex culturing tilapia
- manual sexing
- hybrids
- hormonal sex reversal
- GMT tilapia
- triploids
- high temperarture incubation
how do you manually sex oreochromis?
- males longer pointed dorsal and anal fins
- more developed jaws in males
- color at breeding (males paler)
- males larger
- location of urogenital opening(s)
what is the most difficult tilapia to manually sex?
tilapia
what are the 3 advantages to hybridizing your tilapia?
- do not treat all production fish
- less expensive (labor, material)
- better market
what are the 3 usual tilapia hybrids, and what is the most common of these three?
female O.Mossambicus x male O. hornorun urolepis
female O. niloticus x male O. aurea. MOST COMMON
female O. niloticus x male O. hornorum
how many fish in a tank for breeding? tilapia. think tank diagram.
1 male/2m^2 surface= 200males
+ 400-600females
200-400g each
in 3 cycles thru pond, over one year, how many tilapia fry will you get?
1.5 million, 2-3000 fry/female
