The Blood Volumes of Some Representative Molluscs*

Abstract

1. Individuals of Cryptochiton stelleri, as representatives of the class Placophora, distributed inulin in blood volumes yielding a mean of 43.8% of the wet body weight without shell. Mean cellular water was estimated to be 76%. 2. The two opisthobranch gastropods examined were found to have very large mean blood volumes. Aplysia californicus distributed haemoglobin in 76.2% and mild silver proteinate in 73.1% of the wet body weight. Inulin was distributed in a significantly larger space averaging 79.3% of the body weight, which probably included pericardial and renal spaces. Archidoris sp. distributed inulin in 65.4% of the wet body weight. Mean cellular waters were 74-79% in Aplysia and 83% in Archidoris. 3. Two pulmonate gastropods were studied with inulin which was distributed in a mean space 40.3% of the wet body weight without shell of Achatina fulica, and 36.6% of the wet body weight in Arion ater. The computed cellular waters were 77 and 79%, respectively. 4. Excellent agreement was shown between a marine pelecypod, Mytilus californianus, and a fresh-water pelecypod, Margaritana margaritifera, of similar body size and form. Inulin in the former was distributed in 50.8%, and in the latter inulin and T-1824 in 49% of the wet body weight without shell. The cellular water contents were 80 and 76%, respectively. 5. In a single representative of the Cephalopoda--Octopus hongkongensis, it was possible to demonstrate with T-1824 and with HgS a blood volume averaging 5.8% of the wet body weight, constituting a fluid space distinctly different from the tissue fluid space. Inulin was distributed in the entire extracellular space amounting to 28% of the wet body weight. The cell water which was calculated from the mean values obtained was 77%.

Relationship Between Ammonia Excretion Rates and Hemolymph Nitrogenous Compounds of a Euryhaline Bivalve During Low Salinity Acclimation ,

“…This correction factor assumes that the dry tissue weight equals 35% of the wet weight (tissue and fluid) of the whole animal. This percentage is 2 to 3.7 times higher than measured values determined by other investigators (Martin, Harrison, Huston, and Stewart, 1958;Pierce, 1971a). Thus, the estimated weights used by Lum and Hammen (1964) may have been larger than the true animal dry weight and therefore the ammonia excretion rates calculated would be smaller than the actual excretion rate.…”

THE SURVIVAL OF OSMOTIC STRESS BYSYPHAROCHITON PELLISERPENTIS(MOLLUSCA: POLYPLACOPHORA)

“…of the blood and pericardial fluid of three species of littorinid winkles could be found by Todd (1964). In the chiton, with its sluggish circulation (Martin, Harrison, Huston and Stewart, 1958) and probably very low non-electrolyte content of the blood, the assumed isosmoticity of pericardial fluid and blood seemed justified in view of the gross osmotic changes to be investigated here.…”

“…Possibly only a limited weight loss can occur, a limit which is quickly reached. This would be possible if blood volume is small (44% in CryptocJiiton stelleri; Martin et al, 1958), and if water and/or salts are unable to leave the body tissues, which would occur if the tissue cells have a limited permeability, or can otherwise restrict the outflow of water and ions. p.…”

Hemocyte activation and nodule formation in the giant keyhole limpet, Megathura crenulata

“…Each limpet was sliced in half to separate the foot from the dorsal half containing the shell, mantle, and viscera. These tissues were further sliced to facilitate blood loss, and hung above collection tubes in a cold room at 4 C. After 4 h, the fluid collected from these organs and the hemolymph released during the initial dissection were pooled to provide an approximate estimation of total body hemolymph volume, which is in the range reported in other molluscs (see Martin et al, 1958).…”