Some observations of Octopus joubini reared in an inland aquarium

Octopus joubini Robson were hatched and reared in a closed circulating sea-water system. Mortality was greatest during the period of hatching. The longest surviving octopus lived for 128 days—it had increased its weight × 5, from 0·04–0·19 g, mantle length × 3, from 3–9 mm, head width × 2, from 3–5 mm. Observations of (1) general behaviour, (2) feeding behaviour, (3) social behaviour of the newly hatched octopuses (0–3 days) and the three longest surviving octopuses (93–119 days) are described. In particular it was observed that the older octopuses would readily grasp and eat small live crabs when these were made to touch the suckers or arms. On no occasion did the attacks appear to be visually elicited. This result is discussed with reference to the memory and learning experiments using O. vulgaris. Possible reasons for the limited survival are also discussed.     

CORRELATED MORPHOMETRIC AND BIOCHEMICAL STUDIES ON THE LIVER CELL : II. Effects of Phenobarbital on Rat Hepatocytes

The changes occurring in rat hepatocytes during a 5 day period of treatment with phenobarbital were determined by morphometric and biochemical methods, particular attention being paid to the endoplasmic reticulum. The hepatocytic cytoplasm played an overwhelming part in the liver hypertrophy, while the hepatocytic nuclei contributed to only a moderate extent. The endoplasmic reticulum accounted for more than half of the increase in cytoplasmic volume. The increase in the volume and number of hepatocytic nuclei in the course of phenobarbital treatment was associated with changes in the ploidy pattern. Until the 2nd day of treatment both the rough-surfaced endoplasmic reticulum (RER) and the smooth-surfaced endoplasmic reticulum (SER) participated in the increase in volume and surface of the whole endoplasmic reticulum (ER). Subsequently, the values for RER fell again to control levels, whereas those for SER continued to increase, with the result that by the 5th day of treatment the SER constituted the dominant cytoplasmic element. The specific volume of mitochondria and microbodies (peroxisomes) remained constant throughout the duration of the experiment, while that of the dense bodies increased. The specific number of mitochondria and microbodies displayed a significant increase, associated with a decrease in their mean volume. The phenobarbital-induced increase in the phospholipid and cytochrome P-450 content of the microsomes, as well as in the activities of microsomal reduced nicotinamide-adenine dinucleotide phosphate-cytochrome c reductase and N-demethylase, was correlated with the morphometric data on the endoplasmic reticulum.     

Increased free-cystine content of fibroblasts cultured from patients with cystinosis

The presence of a significantly increased content of free-cystine in skin fibroblasts from both homozygotes and heterozygotes for cystinosis emphasizes the central role of cystine in this disease, even though the primary defect responsible for cystine accumulation is yet to be determined. The studies described in this communication provide evidence that cystine is compartmentalized in a subcellular location in cystinotic cells. In fact, the very growth of cystinotic fibroblasts in the presence more than 100 times the usual content of free-cystine is evidence that the accumulated cystine is not freely dispersed throughout the cell, since would otherwise inhibit many enzymes requiring free sulfhydryl groups for activity (Patrick, 1965). We have no evidence as to whether the cystine is located in a known subcellular organelle or in a previously unrecognized location. Skin fibroblasts may provide a convenient tool to pursue these questions.