LIFE HISTORY STRATEGY (PART 2)

Overview – Life History Patterns 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns ✓

From last lecture Fertilization pattern CostsBenefits External Fertilization-large gamete output -need for synchrony -unpredictable dispersion -gamete dilution -takes advantage of medium Internal Fertilization (no copulation) -large gamete output -unpredictable dispersion -gamete dilution -takes advantage of medium Internal Fertilization (copulation) -energy in mate searching -energy in courtship -less gamete wastage -greater efficiency in reproduction

Developmental Patterns -Kinds of eggs Isolecithal Telolecithal yolk 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Developmental Patterns -Kinds of eggs Isolecithal Telolecithal Cleavage through entire egg Cleavage not through entire egg 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Developmental Patterns -Kinds of eggs Isolecithal Telolecithal Cleavage through entire egg Cleavage not through entire egg Holoblastic Meroblastic 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Developmental Patterns -Kinds of eggs Isolecithal - HoloblasticTelolecithal - Meroblastic 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Developmental Patterns -Kinds of eggs Isolecithal Telolecithal Holoblastic Meroblastic Planktotrophic larvae Lecithotrophic larvae 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Kinds of Development Patterns Free spawning Planktotrophic, free-swimming larvae Settlement and metamorphosis Juvenile Maturation Weakly isolecithal egg Indirect Free spawning Planktotrophic, free-swimming larvae Settlement and metamorphosis Juvenile Maturation Strongly/moderately telolecithal egg Indirect Mating Brooding of embryos Hatch as juvenilesMaturation Strongly telolecithal egg Direct Mating Brooding of embryos Hatch as free- swimming larvae Juvenile Maturation Moderately telolecithal egg Mixed Settlement and metamorphosis 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement – Large Scale 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns 0.2 % recovery 0.18 % recovery 0.2 % recovery Scheltema ‘71

Larval Settlement – Large Scale 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Scheltema ‘71 Larval Settlement – Large Scale 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns Population size Frequency of dispersal

Scheltema ‘71 Larval Settlement – Large Scale 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns North Atlantic Drift Volume of water (m 3 )Total number of larvae North Equatorial Current Equatorial Undercurrent South Equatorial Current 2.45 x x x x x x x x 10 11

Point Conception Larval Settlement Large Scale 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Point Conception Larval Settlement Large Scale Current Patterns 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Point Conception Larval Settlement Large Scale Current Patterns Biogeographical Zones 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Embayment Flushing (Gaines & Bertness, ‘92) 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Wind & Tidal Currents Associated with internal waves

Wind & Tidal Currents Associated with internal waves 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Settlement - Behaviour of Larvae Lobster hatches -photopositive- Drifts in plankton (days/weeks) Preference switches to photonegative Lobster settles and undergoes metamorphosis Metamorphosis to postlarva 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

3. Benthic/Surface Phenomena Pawlik et al, ‘91. Science 251:421 - settlement of reef-building worm Current Speed -low -medium -high (>15 cm/sec) Phragmatopoma 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

3. Benthic/Surface Phenomena Pawlik et al, ‘91. Science 251:421 # settling Current No ‘sampling’Erosion 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Early models Larvae in water column Settle randomlyDifferential mortality Adult distribution More recent view Larvae in water column Passive depositionTesting substrate Settle Adult distribution Not settle 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Passive Deposition -due to 1) sedimentation rate 2) swimming behaviour 3) bottom flow patterns 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Bottom flow patterns Laminar flow 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Bottom flow patterns x x x xx Change in angular velocity 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Experiment on settling and flow Botman et al 1998 coarse sand rich muds Capitella Mercenaria

Experiment on settling and flow Glass beadsMud Flow

Experiment on settling and flow Still water Flow MudBeadsMudbeads Capitellayesnoyesno Mercenarianoyes No preference Conclusion - choice is species specific - Mercenaria couldn’t ‘sample’

General Model Free swimming larva Alternating photonegative & photopositive behaviour Passive deposition and contact with surface Surface texture Chemical cuesContact with conspecifics Attachment 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 1. Conspecifics 2. Microbial films 3. Prey species 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 1. Conspecifics Free fatty acids Larval settlement Phragmatopoma 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 2. Bacterial films Polysaccharides, Glycoproteins Increased searching or metamorphosis 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 3. Prey species - herbivores Settlement induced by GABA 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 3. Prey species - herbivores Gigartina Porphyra Abalone larva In field -not found on either -not induced to settle on whole fronds 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 3. Prey species - carnivores Onchidoris bilamellata Induces settlement 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns

Larval Settlement 3. Prey species - carnivores Phestilla Induces settlement < 500 Da protein (< 10 mM) 1) Fertilization patterns 2) Development patterns 3) Dispersal patterns 4) Settlement patterns