Marine Ecology Exam 2

Iteroparous

spawning possible more than once

Semelparous

spawning only once, then death

Promiscuous

little or no mate choice

Polygamous

one sex has multiple partners

Polyandry

one female, several males

Polygyny

one male, several females

Monogamous

mates stay together exclusively

Gonochoristic

gender fixed, determined early

Hermaphrodites

either both sexes or sex change

Simultaneous Hermaphrodite

eggs and sperm at the same time

Sequential Hermaphrodite

sex change during life (often determined by size)

Viviparous

embryo develops inside the mother and the mother gives live birth

Oviparous

animal that lays eggs, with little or no other embryonic development within the mother

Ovoviviparous

animals develop within eggs that remain in the mother’s body until they hatch or are about to

Abiotic Factors that Affect Dispersal/Repro

moon, currents, tide, seasons, salinity, temperature

Biotic Factors that Affect Dispersal/Repro

pheromones, predation, competition for mates

Factors Affecting Hatching

temperature, oxygen, tides, time of day, currents, moon

Lecithotrophic

with yolk sac, no digestion

Planktotrophic

feed while larvae, digestion

Teleplanic Larvae

larvae forever, born plankton, die plankton

Factors that Trigger Settlement

active choice, chemical cues, physical cues (light)

Gregarious Settling

larvae settle on adults

Migration (Polar Adaptation)

escape to more temperate climate when needed

Resistance (Polar Adaptation)

insulation, low lying, insects have glycerol for wings

Hibernation (Polar Adaptation)

avoid food scarcity and cold

Polikilotherms

cold blooded

Homeotherms

warm blooded

Polar Gigantism

results from slow growth rates in low temperature waters and increased dissolved oxygen in water

Navigation

moving along a course

Migration

moving from one region to another

Homing

returning back to a specific point

Reasons to Migrate

reproductive success and food acquisition

Trail Following

pheromone trails

Piloting

use landmarks to navigate

Path Integration

take a wavy path to get somewhere, but get home in a straight path

Map Navigation

use the earth’s magnetic field

Compass Navigation

use the sun or stars

Olfactory Cues

detection of dimethyl sulfide released by plankton

Satellite Tags

produce radio waves that are received by satellite; antenna has to be above or near water surface to transmit

Archival Tags

records many types of data, which is stored for later retrieval; determines position by environmental data

Acoustic Tags

utilizes sound waves to transmit information using transmitter and hydrophone

Fishery

the resource, the habitat, the people involved

Where Most Fish are Harvested (90%)

within 200 miles of shore

Demersal Species

bottom dwelling species

Pelagic Species

open water species

Reasons for Fishery Declines

overfishing, highly efficient technology, bycatch, overcapacity of fishing fleet

Impacts of Fishery Declines

fishing down the food web, habitat degradation, trophic cascades, change in life history traits

Why Fishery Declines Continue

government subsidies, shifting baselines, increasing demand, lack of adequate fisheries data