Holoplankton

Question 1

What are holoplankton

Answer 1

Permanent plankton

Question 2

Holoplankton diversity and abundance

Answer 2

Relatively low diversity, very high abundance.
Copepods make a significant contribution to global biomass of mesozooplankton.

Question 3

Protozooplankton, Heterotrophic flagellates

Answer 3

Single cells 2-5um dominate biomass and grazing of oligotrophic systems.

Question 4

Protozooplankton feeding

Answer 4

Consume large prey by pallium feeding, tube feeding and direct engulfment.

Question 5

Pallium feeding

Answer 5

Veil covers prey item and digests inside veil and contracts to consume.

Question 6

Protozoos Ciliates

Answer 6

Loricate (shelled) or alorica/oligotrich (without shells)
Shelled ciliates also known as tintinnids
Feed on small prey items using ciliary currents

Question 7

Protozoo, radiolarians

Answer 7

Mineral skeletons.
Numerous needle like pseuopodia radiate from cell.
Vacuoles, liquid droplets, pseupodia aid buoyancy.

Question 8

Protozoos, foraminiefera

Answer 8

Cell surrounded by a carbonate chambered shell.
Network of pseupodia
Mostly benthic 4000sp with a few planktonic
omnivores

Question 9

Hydrozoa, Schypozoa

Answer 9

Deep sea jellies
Mesopelagic features, red, direct dev, biolumin
Undertake DVM from 50-5000m.
Feed on copepods, euphausiids, ostracods.

Question 10

Hydrozoa, siphonophores

Answer 10

Deep sea
Colonial specialized individuals
Cormidium, i unit of zooids within the siphosome.
Carnivores

Question 11

Ctenophora

Answer 11

Global including deep sea
Exclusively carnivorous marine, 150spp
Swim using fused ciliary plates, comb plates.
Bloom-forming, reproduce and grow quickly
Capture prey with sticky colloblasts
Hermaphrodites
Nuda without tentacles, tentaculata with.

Question 12

Molluscs, thecosomata

Answer 12

Thin calcified shells
Foot developed into 2 wing-like lobes
Float and swim by slow flapping of parapodia
Distributed in upper ocean from poles to tropics.

Question 13

Molluscs, gymnosomata

Answer 13

Without shell
Broad wing like foot for flapping
Gelatinous, transparent <5cm
Poles to tropics.
Carnviores feed on heteropods.
Hermaphrodites

Question 14

Chaeotgnatha

Answer 14

Global.
Transparent, bilateral
head, trunk and tail
No circulatory or excretory.

Question 15

Chaeotgnatha head and feeding

Answer 15

Conc of nerves in head
Paired photoreceptive eyes.
Mechano and chemoreceptors
Capture prey using curved chitinous grasping spines around mouth.
Active carnivores

Question 16

Factors to determine what prey to eat

Answer 16

External, light, prey size and motility
Swimming speed relative to prey
Size of grasping spines and mouth.

Question 17

Tunicates, thaliacea

Answer 17

Transparent barrels.
Highly efficient filter feeders of phyto <1um to 1mm.
Bloom forming oceanic spp from oligotrophic to productive waters.
Hermaphrodites with complex metagenic life cycles, asexual and sexual phases.

Question 18

tunicates, salpida

Answer 18

Solitary asexual oozoid and colonial sexual blastozooid.
Stolon emerges from oozoid to produce chain of blastozooids.
Muscle bands incomplete
Often high biomass in low lats.
Feed by swimming and pumping with muscles.

Question 19

Tunicates, doliolida

Answer 19

Complex life cycle involving alternating solitary and colonial zooids.
Typically smaller than salps.
Muscle bands complete

Question 20

Tunicates, appendicularia

Answer 20

Larvaceans, resembling tadpoles.
Small trunk with long tail ~1mm
Secrete mucous ‘house’ every 3 hours to filter feed on nanoplankton, abandon house when blocked.
Hermaphrodite
Direct development

Question 21

Crustaceans

Answer 21

Segmented body in 3 parts
Head thorax abdomen
Pairs of jointed legs, chitin exoskeleton, protein and calcareous material, two pairs of antennae.

Question 22

Ostracods

Answer 22

Mostly warm water and upper 500m
Herbivorous filter feeders
Bivalve carapace to retract in
Antennae and antennules large for swimming

Question 23

Cladocera

Answer 23

Mainly freshwater
Wide global range
Numerous for short periods in coastal and estuaries in summer.
Herbivorous filter feeding.
Parthenogenetic, but also have sexual generation with ‘resting’ eggs.

Question 24

Amphipoda

Answer 24

Open water
Generally have 2 pairs compound eyes.
Abundance in twilight zone
No carapace
Carnivorous on gel zoos

Question 25

Mysidacae

Answer 25

Shrimp like Global Carapace not fused with abdomen Omnivores Stalked eyes

Question 26

Euphausiacea

Answer 26

Most herbivorous filter feeders. Fused carapace and eyes aren't stalked. Significant member of ecosystems, particularly at high lats. Krill

Question 27

Krill

Answer 27

Dominate zoop biomass Food for megafauna Biogeochemical cycling Commercially harvested

Question 28

Copepods

Answer 28

V abundant Dominate most zoop samples, often 60-90%. Occur at all depths Link PP and higher orders calanoids, cyclopoida and harpacticoida are most abundant and important all feeding types

Question 29

Copepod anatomy

Answer 29

No carapace Prosome, head and thorax Compound eye absent Well developed antennae and antennules Urosome lacks appendages Separate sexes

Question 30

Copepods life cycle

Answer 30

Eggs spawned in egg sac Egg hatches into nauplius 6 naupliar stages 6 copepodite stages

Question 31

Copepod calanoid anatomy

Answer 31

Long 1st antennae Biramous 2nd antennae Single egg sac Joint is between 5th and 6th segment

Question 32

Calanoid importance

Answer 32

Dominate plankton in most seas, ~1800 sp Important for fisheries Niche separation between taxa due to size, feeding and breeding. Adapted mouth parts.

Question 33

Copepods, cyclopoids anatomy

Answer 33

shorter 1st antennae uniramous 2nd Two egg sacs Joint between 4th and 5th segment

Question 34

Cyclopoids numbers

Answer 34

~1200 species, mainly freshwater. Fewer marine, 70sp. Many are carnivores or omnivores

Question 35

Harpacticoid anatomy

Answer 35

Very short 1st Biramous 2nd Mostly benthic Wide abdomen

Question 36

Harpacticoid numbers

Answer 36

~3600 sp Mainly epibenthic and contribute to benthic meiofauna Many species graze algal biofilms and bacteria.