Intralamellar blood flow patterns in fish gills

The dimensions of the lamellar vascular sheet in ling cod gills were examined over a range of transmural pressures (delta Plam). The mean vascular sheet thickness (h) increased linearly with delta Plam over the range 30-60 cmH2O, where h = 8.36 + 0.07 delta Plam. The vascular space-to-tissue ratio, however, was unchanged over the pressure range examined. Thus sheet flow equations, formerly derived for the interalveolar wall of the mammalian lungs, can be used to describe blood flow through the lamellae. Predictions were made on the distribution of blood flow within the lamella. When delta Plam and flow are raised, blood flow is redistributed away from the base of the lamella, since regional variations exist in the thickness and the vascular compliance of the lamellar sheet. Variations in the pattern of intralamellar blood flow are likely to affect gas transfer in the gills.

Gill morphometrics, vessel dimensions, and vascular resistance in ling cod, Ophiodon elongatus

The morphology, morphometric relationships, and vascular geometry were established for ling cod gills using fixed tissue and vascular casts. Calculations using Poiseuillian and sheet flow equations permitted predictions of the resistance and the pressure drop in various vessels of the respiratory network in the gill filament. It was found that the afferent lamellar arteriole was the major vascular resistance. Blood transit times through the gills were also calculated and discussed.

Vascular pathways in the gill of ling cod, Ophiodon elongatus

Corrosion plastic casts were made of the gill vasculature in ling cod (Ophiodon elongatus) using methyl methacrylate. The vessels afferent and efferent to the gills are described, as well as the microvasculature of the filament. There is a respiratory network and a venolymphatic network. The venolymphatic network is derived from efferent arteries and thus all cardiac output must pass through the gill lamellae.

Vitamin A and D Potencies of Liver and Intestinal Oils of Red, Black and Ling Cod

The vitamin A potency of the liver and intestines tends to increase with the size of the fish in Sebastodes, Anoplopoma and Ophiodon, and is similar to that reported for halibut. The vitamin D potency of the intestinal oil is low but rather high in red and ling cod liver oils. The percentage of oil in the intestines of these fish is considerably higher than that of halibut.

Observations on Some Pacific Diatoms as the Food of Copepods and Fishes

An investigation to determine what species of diatoms are used as food by different species of copepods: Calanus tonsus, Euchaeta japonica, Metridia lucens, Harpacticus uniremis, and Diosaccus spinatus. Also to determine the food chains between diatoms, copepods, and the following fish: Pacific herring, Clupea pallasii; chum salmon, Oncorhynchus keta; spring salmon, O. tschawytscha; dogfish, Squalus suckleyi; ling cod, Ophiodon elongatus; rockfish, Sebastodes caurinus; starry flounder, Platichthys stellatus; lemon sole, Parophrys vetulus; yellow-finned surffish, Damalichthys vacca; blue perch, Taeniotoca lateralis, and yellow shiner, Cymatogaster aggregatus. Stomach, intestines, and excreta were examined for the presence of diatoms. Almost all the common diatoms were found to be used as food by the copepods. The copepods and herring were found to be important links in the food chains between diatoms and the larger fishes.

The Nutritive Value of Marine Products: X. Proximate Analysis of Ling Cod

Separate proximate analyses of the flesh and skin of three freshly-caught ling cod (Ophiodon elongatus) from the east coast of Vancouver island are reported. Average percentages of protein in the flesh and skin were 18.1 and 26.9 (moist) or 87.0 and 88.5 (dry); ash, 1.2 and 2.5 (moist); fat, negligible; Calories per 100 g. (moist), 81 and 117.

THE NUTRITIVE VALUE OF MARINE PRODUCTS V. THE VITAMIN A CONTENT OF LING COD-LIVER OIL PRELIMINARY NOTE

The liver oil of the Pacific coast Ling cod has been examined for vitamin A by both biological and colorimetric methods. The oil is very rich in vitamin A, the least potent sample containing 20,000 rat units per gram.