Turbellarian taxonomic database

Proporus lonchitis Notes

[translated from Doerjes 1971] Description of Proporus lonchitis type locality: Droebak, Norway; 50-200 m depth, August 1955 material: 1 wholemount, 7 sets serial sections no live observations holotype a sagittal series, in Naturhist. National Museum, Stockholm along with paratype fixation: sublimat/formol/acetic-acid section staining with hematoxylin/eosin section thickness 4-5 um Habitus: roll-shaped body, 1.8 mm long after fixation front and hind ends gently rounded circular in cross-section whole mount with inbowing of body wall just behind statocysts, but this not necessarily a constant character inner organization what stands out in embedded animal: nerve complex of brain with statocyst pharynx tube behind brain, with mouth copulatory organ at posterior tip male and female germ tissue testes dorso-lateral, in female-mature animal only as small side bands in hind 1/2 body converge toward copulatory organ female germ cells take up most of posterior 2/3 of body conspicuous lack of maturation gradient to eggs: young and mature oocytes and eggs mixed epidermis of distincts heights: front body with insunk, flat epithelium hindbody with twice that thickness and its epithelial nuclei embedded in granular, weakly vacuolated ground substance from body tip posteriorly stepwise from fully insunk to non-insunk pear-shaped adenal slime glands distributed in peripheral parenchyma narrow secretions penetrate body-wall musculature and epidermis, with necks between cilia eosinophilous secretion, weakly granular no frontal gland or rhabdite glands seen few epidermal-regeneration bodies always in peripheral parenchyma ... musculature like that of other acoels: outer circular, inner longitudinal inner musculature only weakly developed parenchyma: peripheral parench spongy, and weakly lamellated in middle of body especially well developed in forebody in hindbody only as peripheral nucleus-bearing layer, between bodywall musculature and inner organs border to central parenchyma punctuated with irregular protrusions into it central parenchyma granular gut space reaches over posterior 2/3 of body, narrowed by voluminous ovaries and copulatory organ begins at tubular pharynx at level of first 1/4 body mouth at transition between first and second 1/4 body from it, pharynx reaching in dorso-caudal direction pharynx of simplex type = simple invagination of ventral epidermis circular and longi muscles over whole length numerous long-necked insunk glands penetrate this musculature secretions slightly eosinophilic proximal opening of pharynx with obvious musculature that could be fixators or dilators beginnings of weak fibers in transitional zone between pharynx and gut seen at high mag. nervous system visible only in forebody brain mass insunk, encompasses statocyst completely 2 clear nerves toward frontal end, 2 toward lateral body wall not easily followed in these sections 2 pairs lateral nerves to body periphery that branch tree-like at level of body-wall muscles, lost into peripheral parenchyma male reproductive organs male germ tissue shortly behind midbody, reaches in 2 dorsolateral fields, narrowed by ovaries spermatogonia go from peripheral tissue band of peripheral parenchyma and come together in formation place to ball-like follicles where spermatogenesis occurs narrow club-shaped sperm grow and differentiate toward vesicula seminalis copulatory organ simple invagination of body wall like pharynx terminal pore connects inwards to a spacious ciliated antrum tube antrum can widen as ring-shaped fold in front of muscular ves. sem. numerous long-necked accessory glands insunk in atrial musculature, penetrate epithel. eosinophilic secretions into antrum lumen proximal sperm vesicle of weak musculature, with cellular structure at entrance part female reproductive organs no female helping organs unpaired ovary reaches over posterior 2/3 of body, filling whole body width formation zone is exceptional: no local fixed body position, rather in whole ventral side of posterior 2/3 body oogonia differentiate out of peripheral layer of peripheral parenchyma, move dorsally therefore get young and mature eggs together oocytes more or less rounded in all stages of development, no lobopodia

Return to Proporus lonchitis