New Zealand Journal of Zoology abstracts

---

Ultrastructural observations on Temnocephala minor (Platyhelminthes, Temnocephaloidea), including notes on endocytosis

J. B. WILLIAMS

Department of Zoology
University of Canterbury
Private Bag 4800
Christchurch, New Zealand

Abstract  Ultrastructural characteristics of the epidermis, rhabditogenic cells, intestinal epithelium, and protonephridial system of Temnocephala minor are described. The epidermis has non-locomotory cilia, with strongly developed, cross-striated rootlets embedded in the epidermal syncytium. The rhabdite-synthesising cells, in contrast with those of other temnocephalids, are not deeply invaginated by parenchymal cell processes. The intestinal epithelium is cellular, unciliated, and without microvilli; it is bordered by narrow lamellae, which fuse together to form pinocytotic vesicles enclosing nutrient droplets and particles from the lumen. Associated lysosomes contain myelin figures, dense bodies, and filamentous debris. Digestion probably proceeds by a combination of intraluminar and intracellular processes. Protonephridia are of the rhabdocoel turbellarian type. Bacteria in the cavities of the main excretory vessels are endocytosed intact by the tubule cells, and the sequestered micro-organisms show evidence of lysosomal degradation. The tubule cells contain glycogen rosettes, and cup-shaped mitochondria with concavities filled by modified cytoplasm.

Keywords  Platyhelminthes; Temnocephala minor; ultrastructure; epidermal cilia; rhabditogenic cells; intestine; protonephridia; endocytosis; pinocytotic vesicles; mitochondria

PDF file of entire paper: medium quality (2306K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page