Benthic invertebrates

Question 1

what are the oceanic divisions starting from the bottom up

Answer 1

1) hadalpelagic
2) abyssalpelagic
3) bathypelagic
4) mesopelagic
5) epipelagic

Question 2

what does epibenthic mean

Answer 2

attached to a hard substarum or rooted to a shallow depth below seabed surface

Question 3

what are some examples of benthic invertebrate feeding modes

Answer 3

• carnivores
• herbivores
• filter feeders
• deposit feeders

Question 4

what are some examples of benthic invertebrate feeding modes

Answer 4

• carnivores
• herbivores
• filter feeders
• deposit feeders

Question 5

how do suspension feeders feed

Answer 5

capture particles from the water either
1) passively- using existing currents
2) actively - generating own currents

Question 6

what orders belong to the class cirripedia, superorder thoracica

Answer 6

1) sessilia - acorn barnacles
2) pedunculata - goose barnacles

Question 7

what are brittle star beds

Answer 7

benthic inverterbrates in which some species can be found in large numbers. Found in british waters and variable in size

Question 8

what are the two clades of polychaetes (a type of annelid worm)

Answer 8

1) errantia
2) sedentaria = include colonial, reef building forms with fans of head tenacles

Question 9

how do deposit feeders feed

Answer 9

ingest sediment and digest organic content, many are also scavengers

Question 10

outline some characteristics of isopods

Answer 10

• dorso-ventrically falttened
• aquatic species are benthic
• numerous deep sea species
• some important parasitic forms

Question 11

outline some characteristics of amphipoda

Answer 11

laterally compressed
can be divided into gammarids (90% all amphipods) and hyperiids (all planktonic)

Question 12

what is a radula

Answer 12

unique to molluscs it is a ribbon of chitin covered in rows of backward facing teeth with a moveable fleshy base

Question 13

outline the cycle between urchins and kelp beds

Answer 13

1) removal or urchin predators increased sea urchin density causes destructive grazing which leads to barren grounds
2) disease in urchins causes mass urchin mortality which helps recruit and reestablish kelp

Question 14

out do cephalopods feed

Answer 14

all cephalopods are carnivores and prey is captured with tentacles and moved to powerful, chitinous beak

Question 15

what are asteroids

Answer 15

a species with a centeral mouth with radial digestive system
short armed swallow entire prey vs long armed which evert stomach and digest outside
bivalbve feeders

Question 16

what are stomatopods

Answer 16

e.g. mantis shrimps
fast and efficent predators
- spearers eat soft prey
clubbers eat hard prey

Question 17

what are decapods

Answer 17

the largest and most diverse group within the malacostraca e.g. cray fish and crabs
- five pairs of pereopods
first pair usually with clasws

Question 18

give some examples of common decapods in british rock pools

Answer 18

• prawns
• brown shrimp
• velvet swimming crab