Ⅰ Selectively Important Features of the Deep-sea Environment

A. Physical characteristics

B. Food supplies in the deep sea

Ⅱ Adaptations to Hydrostatic Pressure

Ⅲ Metabolic Rates in the Deep sea 1. Pressure Adaptations to Enzyme Kinetic Properties 2. Pressure-related Differences in Catalytic Efficiency 3. Pressure Effects on Protein Structure 4. Adaptations in Lipid-Based Systems 5. The Interplay of Physical and Biological Factors

Ⅳ The Hydrothermal Vents: Abundant Life in the Deep sea 1. Sulfide-based Food Webs at the Hydrothermal Vents 2. Metabolic Rates of Hydrothermal Vent Animals 3. Avoidance of Poisoning by Hydrogen Sulfide

Ⅴ Prospective

Metabolic Potentials of Deep-Sea Fishes

Metabolic Potentials of Deep-Sea Fishes Ⅰ Selectively Important Features of the Deep-sea Environment

Ⅱ Adaptations to Hydrostatic Pressure Ⅲ Metabolic Rates in the Deep sea

1. Pressure Adaptations to Enzyme Kinetic Properties 2. Pressure-related Differences in Catalytic Efficiency 3. Pressure Effects on Protein Structure 4. Adaptations in Lipid-Based Systems 5. The Interplay of Physical and Biological Factors Ⅳ The Hydrothermal Vents: Abundant Life in the Deep sea

1. Sulfide-based Food Webs at the Hydrothermal Vents 2. Metabolic Rates of Hydrothermal Vent Animals 3. Avoidance of Poisoning by Hydrogen Sulfide

Ⅴ Prospective

Ⅱ Adaptations to Hydrostatic Pressure Ⅲ Metabolic Rates in the Deep sea

deep-sea fish fauna

pelagic fish demersal fish

Water column of open water

Benthically benthopelagically sea floor

lanternfish (Myctophidae)

silver hatchethshes (Gonostomatidae)

gonostomatids

viperfish (Chauliodonitdae)

black stomiatoids (Stomiatoidei)

shallow-water codfish rattails (Macrouridae)

deep-water cods (Moridae)

brotulids (Ophidioidei)

eelpouts (Zoarcidae)

slickhead (Alepocephalidae)

shark rays (Elasmobranchii)

deep-sea angler (Ceratioidei)

whalefish (Barbourisidae)

gulper eels (Saccopharyngidae)

chimaeras

eels

salmonids

shallow ( ●▲○ )

deep ( □■ ▲ ) △

shallow ( ●▲○ )

deep ( □■ ▲ ) △

Ⅲ Metabolic Rates in the Deep sea 1. Pressure Adaptations to Enzyme Kinetic Properties

●

▲

○

Deep Shallow

□

■

△

◆

Ⅲ Metabolic Rates in the Deep sea

2. Pressure-related Differences in Catalytic Efficiency

Ⅲ Metabolic Rates in the Deep sea

3. Pressure Effects on Protein Structure

Ⅲ Metabolic Rates in the Deep sea4. Adaptations in Lipid-Based Systems

In summary, the biochemical systems of deep-living animals differ both qualitatively and quantitatively from those of shallow-living animals. Adaptations in proteins leading to reduced perturbation by hydrostatic pressure facilitate survival in the deep sea. Adjustments in the concentrations of enzymes of energy metabolism in locomotory capacities that are suited for life in a dark, food-poor environment. Pelagic animals from the typical deep-sea (benthic species have received very little physiological and biochemical study, so we can say little about their metabolic properties) thus seem admirably designed for a life in slow motion.

Ⅲ Metabolic Rates in the Deep sea 5. The Interplay of Physical and Biological Factors 1. Rates of metabolism in typical deep-sea environments. 2. Factors selecting for low metabolic rates in the deep sea. 3. Mechanisms used to achieve low metabolic rates in the deep sea.

Ⅲ Metabolic Rates in the Deep sea

a. Rate of metabolism in typical deep-sea environment

b. Factors selecting for low metabolic rates in the deep sea

c. Mechanisms used to achieve low metabolic rates in the deep sea

Ⅳ The Hydrothermal Vents: Abundant Life in the Deep sea

Ⅳ The Hydrothermal Vents: Abundant Life in the Deep sea 1. Sulfide-based Food Webs at the Hydrothermal Vents 2. Metabolic Rates of Hydrothermal Vent Animals 3. Avoidance of Poisoning by Hydrogen Sulfide

Ⅴ Prospective

Deep-water habitats form by far the largest ecosystems on the planet. Enough is known about the lives of deep-water fishes, despite the difficulties inherent in such study, to give a fairly coherent picture of their overall ecology. Series from the various large national deep-water expeditions have allowed the working out of detailed life histories, food webs, species associations and biogeography. The particular conditions that characterize deep water everywhere have shaped the nature of deep-water fishes, and probably the most important factor at play has been the logarithmic decline of food energy available with increasing depth. Comparative study of deep-pelagic, deep-demersal, and deep-lake fishes reveals interesting and intriguing differences with respect to the adaptations and probable history of the faunas in each of these habitats. Deep-water fishes have long been insulated from any significant human impacts, but deep-water fisheries, species introductions, pollution and other ecosystem tamperings are changing this situation rapidly. Can these remarkable, enduring and well-adapted species and assemblages withstand the developing onslaught ?