The ultrastructure of nematocysts from the fishing tentacle of the Hawaiian bluebottle, Physalia utriculus (Cnidaria, Hydrozoa, Siphonophora)

• Published in: Hydrobiologia Vol. 489; no. 1-3; pp. 139 - 150
• Main Authors: YANAGIHARA, Angel A, KUROIWA, Janelle M. Y, OLIVER, Louise M, KUNKEL, Dennis D
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-12-2002; Springer Nature B.V
• Subjects: Biological and medical sciences; Cnidaria; Cnidaria. Ctenaria; Coastal waters; Comparative analysis; Fibers; Fishing; Fundamental and applied biological sciences. Psychology; Hydrozoa; Invertebrates; Light microscopy; Physalia utriculus; Siphonophora; Australia; Coelenterata; Ultrastructure; cnidome; nematocyst; Morphology; anisorhiza; Cnidaria; bluebottle; Hydrozoa; Invertebrata; Scanning transmission electron microscopy; Physalia utriculus
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1023/A:1023272519668

Fishing tentacle nematocysts of the hydrozoan, Physalia utriculus, from Hawaiian coastal waters, were examined by light microscopy, as well as by scanning and transmission electron microscopy (SEM and TEM). Hawaiian P. utriculus has been assumed to be conspecific with the Australian morph based on general macroscopic descriptions. Ultrastructural examination using SEM and TEM revealed that the cnidome was composed of two sizes of heterotrichous anisorhizas as well as rare rhopoloids (less than one observed per 1000 nematocysts). Beyond classification of the cnidome of Hawaiian P. utriculus, an unprecedented morphological structure was observed. Specifically, SEM revealed fibers (<1 μm in diameter) along the spiral crest of spines of some discharged tubules of P. utriculus anisorhizas. A hypothetical model of spine morphogenesis was formulated based on comparative analysis of hundreds of discharged tubules.[PUBLICATION ABSTRACT]