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Fish telemetry studies now routinely collect positional and depth data, yet analytical approaches that integrate three-dimensional data are limited. Here we apply the potential path volume (PPV) model, a method previously developed to estimate habitat volume based on rates of avian movement, to free-swimming fish. Using a telemetry dataset of white sucker (Catastomus commersonii) from Turkey Lake (Ontario, Canada), we evaluated the effects of the number of spatial positions and different methods of selecting swim speed (v swim ), a key parameter for PPV models, on habitat volume estimates. We subsequently compared habitat volume estimates and habitat overlap among white sucker pairs from the PPV models to those calculated using kernel utilization distribution-based approaches. The number of spatial positions in the PPV model had a significant effect on habitat volume estimates, whereas the magnitude of the v swim parameter or its specificity (constant value vs. fish-season specific parameter values) did not affect habitat volume estimates. The PPV method resulted in larger habitat volume estimates and greater habitat overlap estimates among fish pairs relative to those obtained from a three-dimensional kernel utilization distribution method. The PPV model is a useful analytical tool that, by incorporating potential animal movement into habitat use evaluations, can help answer key ecological questions and provide insight into fish space use in a wide range of conservation and management applications., (© 2024 His Majesty the King in Right of Canada. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles. Reproduced with the permission of the Minister of Fisheries and Oceans Canada.)

A case of traumatic haemobilia following closed injury is presented. A false aneurysm of the right hepatic artery was successfully treated by inadvertent subintimal stripping of the origin of the right hepatic artery.

Myelographic changes after spinal operation are often difficult to interpret especially with regard to the differentiation between arachnoiditis and recurrent disc prolapse. The radiological appearances using iophendylate (Myodil) and the distinguishing features are discussed and illustrated.

Hiatal hernia with ulceration at the level of the diaphragm is a well-recognized and not uncommon condition. These ulcers may be simple gastric ulcers in patients who coincidentally have a hiatal hernia, or they may be related to trauma of the stomach against the diaphragm. They are not always readily detected on barium study. The clinical and radiological features in 3 recent cases are described, together with a brief review of the literature.

Three patients who developed obstructive jaundice after mastectomy for carcinoma of the breast are presented. Prognosis is invariably poor as widespread metastases are usually present at the time of presentation. The pathogenesis, investigations and clinical significance are discussed.

Caecal volvulus is usually associated with a twisted caecum, seen to occupy the umbilical area or left hypochondrium on radiography. Caecal bascule refers to the form of volvulus in which the distended caecum is situated within the pelvis. The caecal bascule type of obstruction is uncommon, and clinical and radiological appearances may be confusing. Two cases are presented and the incidence, pathogenesis and radiological features are discussed.

The computed axial tomographic (CAT) findings in 22 children with intracranial neoplasms are presented. CAT offers a rapid, non-invasive method of assessing the locality and extent of these tumours, as well as the presence of calcification and hydrocephalus. CAT is of value in the follow-up treatment, but an absolute histological diagnosis is not always possible.