Giant isopods are large isopods in genus Bathynomus, reaching up to 50 cm in length. They resemble woodlice with dorsal compression and calcareous exoskeleton. Have compound eyes with nearly 4,000 facets and two pairs of antennae. Store substantial organic reserves in midgut gland and fat body
Pelagic fish live in ocean or lake waters, between bottom and shore. Marine pelagic environment covers 1,370 million cubic kilometres. Fish range from small forage to large apex predators. Many swim in schools weighing hundreds of tonnes
Deep-sea fish live below photic zone (epipelagic) in darkness. Only 2% of marine species inhabit pelagic environment. Deep sea contains 90% of ocean volume in darkness. Bathypelagic (1,000-4,000m) and abyssopelagic (4,000-6,000m) zones exist
Oceans cover 70.8% of Earth's surface and contain 97% of Earth's water. Five main oceans: Pacific, Atlantic, Indian, Antarctic/Southern, Arctic. Ocean temperature ranges from -2°C near poles to 30°C at surface
Each gas in a mixture has a partial pressure as if occupying its own volume. Total pressure of ideal gas mixture equals sum of partial pressures (Dalton's Law). Partial pressure measures thermodynamic activity of gas molecules. Gases dissolve and react according to partial pressures, not concentrations
World's deepest oceanic trench located 200 km east of Mariana Islands. Measures 2,550 km in length and 69 km in width. Maximum depth reaches 10,984 meters at Challenger Deep. Water pressure at bottom exceeds 1,071 times sea level