Organ of Bellonci of an Antarctic crustacean, the marine isopod Glyptonotus antarcticus

✍ Scribed by Jean Chaigneau; Colette Besse; Peter P. Jaros; Gilbert Martin; J. Wolfgang Wägele; Axel Willig

• Book ID: 102904339
• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 1019 KB
• Volume: 207
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1052070202

✦ Synopsis

The paired organ of Bellonci protrudes from the optic lobe of the giant Antarctic isopod, Glyptonotus antarcticus. It is linked to the cortex by a broad peduncle. No connection to the cuticle or "sensory pore organ" was found. A cluster of sensory-like cells forms two outer ciliary segments branching into numerous microvilli with microtubules. The putative sensory somata are irregular in shape and contain a very high density of glycogen granules. The two outer segments sprout from two pits of the soma in different directions, forming a right angle. Glial cells wrap around the sensory cells and also delimit lacunae into which bundles of microvilli project. These lacunae contain electron-dense granules of small size and with species-specific patterns. Lacunae and dense granules show features typical of a degeneration process in the sensory cells. This general morphology corresponds to the unilobular type of organ of Bellonci, known in other isopods; it differs from the plurilobular type with onion bodies found in other Crustacea.