15
assimilation efficiency
Archiannelida formerly separate phylum, or class of the phylum Annelida, now
regarded as a variety of modified Polychaeta, mainly belonging to the meiofaunal (--"7meiobenthos), hence microscopic, worms with simplified structure,
usually without setae. Nervous system unsegmented, in or directly under the
epidermis. Example: Polygordius.
archipelago sea area that contains numerous islands, or the island group itself.
areal distribution horizontal distribution of organisms over the earth; area
occupied.
arrow worm --"7Chaetognatha.
Arthropoda (arthropods) phylum of segmented animals of which the body is
entirely covered with a chitinous exoskeleton or cuticula. The legs and other
appendages are articulated. This phylum comprises, with at least three quarters of a million species described, more than three times the total of all
other currently known species. Arthropoda are divided into the subphyla
Trilobita (fossil), Chelicerata (classes Merostomata or horseshoe crabs: Limulus
sp.; Arachnida or spiders, scorpions, ticks, and mites; Pycnogonida or sea
spiders), Crustacea and Uniramia (classes: Insecta, Chilopoda, Diplopoda,
Symphyla, and Pauropoda).
Aschelminthes (syn. Nemathelminthes) heterogenic group of small animals
(microscopic to several mm), marine and freshwater, that used to be regarded as one phylum: Aschelminthes, but that at present is divided into the separate phyla: Gastrotricha, Nematoda, Rotifera, Nematomorpha (parasitic in
Arthropoda), Acanthocephala, Kinorhyncha, loricifera, Priapulida and, Gnathostomulida
(microscopic, interstitial in anaerobic mud).
Ascidiacea class of the subphylum Urochordata or Tunicata (phylum Chordata), solitary or colonial, sessile tunicates (sea squirts). The saclike body wall is tough
and has two openings on top: the buccal inhalant siphon, and the atrial
siphon. They are filter feeders, only some deep-sea species are carnivores.
Common as marine fouling organisms (e.g., on ships). (Figure see p. 16)
assimilation incorporation of digested food and other materials, after absorption, into living protoplasm. Includes CO 2 -assimilation in plants, the uptake
of CO 2 from water or air, during photosynthesis.
assimilation efficiency ratio between utilized energy and total energy received,
e.g., the portion of light fixed by plants of the total amount of light passing
the vegetation, or the portion of food metabolized (and thus not egested
undigested) of the total food taken up. Low (ca. 1 %) in light fixation by
assimilation efficiency
Archiannelida formerly separate phylum, or class of the phylum Annelida, now
regarded as a variety of modified Polychaeta, mainly belonging to the meiofaunal (--"7meiobenthos), hence microscopic, worms with simplified structure,
usually without setae. Nervous system unsegmented, in or directly under the
epidermis. Example: Polygordius.
archipelago sea area that contains numerous islands, or the island group itself.
areal distribution horizontal distribution of organisms over the earth; area
occupied.
arrow worm --"7Chaetognatha.
Arthropoda (arthropods) phylum of segmented animals of which the body is
entirely covered with a chitinous exoskeleton or cuticula. The legs and other
appendages are articulated. This phylum comprises, with at least three quarters of a million species described, more than three times the total of all
other currently known species. Arthropoda are divided into the subphyla
Trilobita (fossil), Chelicerata (classes Merostomata or horseshoe crabs: Limulus
sp.; Arachnida or spiders, scorpions, ticks, and mites; Pycnogonida or sea
spiders), Crustacea and Uniramia (classes: Insecta, Chilopoda, Diplopoda,
Symphyla, and Pauropoda).
Aschelminthes (syn. Nemathelminthes) heterogenic group of small animals
(microscopic to several mm), marine and freshwater, that used to be regarded as one phylum: Aschelminthes, but that at present is divided into the separate phyla: Gastrotricha, Nematoda, Rotifera, Nematomorpha (parasitic in
Arthropoda), Acanthocephala, Kinorhyncha, loricifera, Priapulida and, Gnathostomulida
(microscopic, interstitial in anaerobic mud).
Ascidiacea class of the subphylum Urochordata or Tunicata (phylum Chordata), solitary or colonial, sessile tunicates (sea squirts). The saclike body wall is tough
and has two openings on top: the buccal inhalant siphon, and the atrial
siphon. They are filter feeders, only some deep-sea species are carnivores.
Common as marine fouling organisms (e.g., on ships). (Figure see p. 16)
assimilation incorporation of digested food and other materials, after absorption, into living protoplasm. Includes CO 2 -assimilation in plants, the uptake
of CO 2 from water or air, during photosynthesis.
assimilation efficiency ratio between utilized energy and total energy received,
e.g., the portion of light fixed by plants of the total amount of light passing
the vegetation, or the portion of food metabolized (and thus not egested
undigested) of the total food taken up. Low (ca. 1 %) in light fixation by