Lecture 29- Living at depth

Question 1

when are fish considered deep sea fish?

Answer 1

if they live below the photic or epipelagic zone.

Question 2

how is oxygen derived within the epipelagic zone?

Answer 2

via photosynthesis and interaction with the atmosphere.

Question 3

what is the oxygen minimum zone phenomenom?

Answer 3

low ozygen at the mesoplelagic zone and also where nutrients are most abundant!

Question 4

why is the deep sea considered an exteremely hostile environment?

Answer 4

average temperature between -1.8 adn 3 degrees or as extreme as 350 degrres near the hydrothermal vent! atmospheric pressure felt by a human in the abyssopelagic would be 800,000 kg

Question 5

do hydrothermal vents have low or high fish diversity?

Answer 5

low the eelpout is the apex predator

Question 6

describe the lanternfish:

Answer 6

account for as much as 65% of all deep sea fish biomass
they are small and have specifes specific patterns of photophores.

During the daylight hours, lanternfish remain within the meso and bathylpelaic zone. towards sundown the fish rises into the epipelagic zone to consume zooplankton which reduces their risk of predation. They then descend back down to depths.

Their photophores plays several roles including mate attraction and camoflauge from both predator and prey

300-1500m

Question 7

describe the bristlemluth:

Answer 7

they have elongated bodies with a number of green or red light producing photophores! They have odd, equalliy sized bristle like teeth! they feed on small prey they attack from below. They do not migrate but have photophores like lantern fish,

4000m

Question 8

describe oarfish:

Answer 8

are large, greatly elongated fish. found in temperate and tropical oceans at a max depth of 3000 m. oarfish filter feed on organisms ranging from zooplankton to small fish. The oar fish does not swim horizontally instead vertically!

Question 9

describe the frilled shark:

Answer 9

living up to 1500m. Considered a living fossil, they have open lateral line, enlarged head, fin structure and placement. They have around 300 needle like teeth specialized at grabbing invertebrates and have longest known gestation at 3 and 1/2 years

Question 10

describe the goblin shark:

Answer 10

rare species of deep-sea shark, seen at depths greater than 100m. Has elongated flattened snout and highly protrusible jaws containing priminent nail like teeth.

Question 11

describe blob sculpins:

Answer 11

their body is covered in tiny spine-like cirri, giving them a prickly appearance. Their deflated appearance is due to extremely low muscle tone which is typical of many deep sea species. They are largely sedentary, content to just wait for food. they are found in benthic abyssal regions of the pacific ocean.

Question 12

describe the viperfish:

Answer 12

it has a diel migration pattern ranging from 80-2000m each day! It uses bioluminenesnce to fish and communicate with conspecifics. it uses fang like teeth to immobilize pre and would not able to close its mouth because of its teeth except they curve around its head.

Question 13

describe snail fish:

Answer 13

have been seen at depths greater than 8000 m so could be the deepest fish on this planet. they are transperent and boneless and little more than guts in a condom. They also have extreme levels of the chemical trimethylamine oxide which protects proteins from damage caused by living under pressure.

Question 14

what is the debate about the cusk eel

Answer 14

one was found possibly at 9000 m but didnt have a great method of testing this with an open net.

Question 15

common adaptations seen in deep sea fish?

Answer 15

1. soft and squishy
2. photophores
3. world wide distribution