Biomaterial Database

Are the funnel-canal organs the 'campaniform sensilla' of the shore crab, Carcinus maenas (Decapoda, Crustacea)? II. Ultrastructure. 1984

M Schmidt, and W Gnatzy

The funnel-canal organs on the dactyls of the shore crab, Carcinus maenas, are innervated by 3-24 sensory cells with unbranched dendrites, which attain a length of 500-1400 micron. The outer dendritic segments are enclosed in a dendritic sheath and pass through the cuticle within a canal. Two dendrite types can be distinguished according to ultrastructural criteria: Type I has a long ciliary segment, A-tubules with an osmiophilic core and arms, and a thick ciliary rootlet. Type II possesses only a short ciliary segment and a thin ciliary rootlet. Each funnel-canal organ contains two type-I dendrites. Their ciliary bases appear a few micron distal to those of the type-II dendrites (1 to 22 in number). Two inner and two to eight outer enveloping cells belong to a sensillum. The innermost enveloping cell contains a large scolopale. In the second enveloping cell single scolopale rods are present. Thus, the funnel-canal organs are characterized by structural features typical for mechanosensitive scolopidia, on the one hand, and for chemoreceptors, on the other. Therefore, the funnel-canal organs are very likely bimodal sensilla (contact chemoreceptors). A comparison with other arthropod sensilla shows that cuticular mechanoreceptors of aquatic crustaceans generally exhibit a 'scolopidial' organization.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008465	Mechanoreceptors	Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.	Golgi Tendon Organ,Golgi Tendon Organs,Krause's End Bulb,Krause's End Bulbs,Mechanoreceptor,Mechanoreceptor Cell,Meissner's Corpuscle,Neurotendinous Spindle,Neurotendinous Spindles,Receptors, Stretch,Ruffini's Corpuscle,Ruffini's Corpuscles,Stretch Receptor,Stretch Receptors,Mechanoreceptor Cells,Bulb, Krause's End,Bulbs, Krause's End,Cell, Mechanoreceptor,Cells, Mechanoreceptor,Corpuscle, Meissner's,Corpuscle, Ruffini's,Corpuscles, Ruffini's,End Bulb, Krause's,End Bulbs, Krause's,Krause End Bulb,Krause End Bulbs,Krauses End Bulb,Krauses End Bulbs,Meissner Corpuscle,Meissners Corpuscle,Organ, Golgi Tendon,Organs, Golgi Tendon,Receptor, Stretch,Ruffini Corpuscle,Ruffini Corpuscles,Ruffinis Corpuscle,Ruffinis Corpuscles,Spindle, Neurotendinous,Spindles, Neurotendinous,Tendon Organ, Golgi,Tendon Organs, Golgi
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D011984	Sensory Receptor Cells	Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.	Nerve Endings, Sensory,Neurons, Sensory,Neuroreceptors,Receptors, Neural,Neural Receptors,Receptors, Sensory,Sensory Neurons,Sensory Receptors,Nerve Ending, Sensory,Neural Receptor,Neuron, Sensory,Neuroreceptor,Receptor Cell, Sensory,Receptor Cells, Sensory,Receptor, Neural,Receptor, Sensory,Sensory Nerve Ending,Sensory Nerve Endings,Sensory Neuron,Sensory Receptor,Sensory Receptor Cell
D003386	Brachyura	An infraorder of chiefly marine, largely carnivorous CRUSTACEA, in the order DECAPODA, including the genera Cancer, Uca, and Callinectes.	Blue Crab,Callinectes sapidus,Carcinus maenas,Crab, Blue,Crab, Common Shore,Crab, Green,Crabs, Short-Tailed,Crabs, True,Green Crab,Uca,Common Shore Crab,European Shore Crab,Blue Crabs,Brachyuras,Carcinus maena,Common Shore Crabs,Crab, European Shore,Crab, Short-Tailed,Crab, True,Crabs, Blue,Crabs, Common Shore,Crabs, Green,Crabs, Short Tailed,Green Crabs,Shore Crab, Common,Shore Crab, European,Shore Crabs, Common,Short-Tailed Crab,Short-Tailed Crabs,True Crab,True Crabs,Ucas,maenas, Carcinus
D003712	Dendrites	Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.	Dendrite
D005121	Extremities	The farthest or outermost projections of the body, such as the HAND and FOOT.	Limbs,Extremity,Limb
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia