Discovery reports (1941) Discovery reports discoveryreports20inst Year: 1941 PHOTOPHORES OF DECAPOD CRUSTACEA 321 remainder of its length, another 560//,, it slopes obliquely inwards on the roof of the branchial chamber, so that its posterior end lies immediately above the most anterior gill. Fig. 5. Transverse section through the photophore in the roof of the branchial chamber of Sergestes corniculum, a little behind the level of the section shown in Fig. 2. Fixed Duboscq, Mallory's triple stain, chitinous lens; connective tissue; nucleus of chitogenous epithelium
Discovery reports (1941) Discovery reports discoveryreports20inst Year: 1941 PHOTOPHORES OF DECAPOD CRUSTACEA 321 remainder of its length, another 560//,, it slopes obliquely inwards on the roof of the branchial chamber, so that its posterior end lies immediately above the most anterior gill. Fig. 5. Transverse section through the photophore in the roof of the branchial chamber of Sergestes corniculum, a little behind the level of the section shown in Fig. 2. Fixed Duboscq, Mallory's triple stain, chitinous lens; connective tissue; nucleus of chitogenous epithelium; nucleus of photogenic ccW; photogenic cell. The structure of the streak is indicated in Fig. 5. It is composed of extremely narrow columnar cells (Fig. 5, ), their limits only partially defined, converging on a slight thickening of the integument (Fig. 5, ) forming the roof of the branchial chamber. In conformity with this arrangement the cells are tapered, the elongated nuclei (Fig. 5, ) occupying the inner broader ends, which show a denser cytoplasm than the narrower ends. The nuclei, which are in general about half the length of the cells, possess regularly scattered chromatin producing a granular appear- ance. Some 30-40 cells make up the breadth of the organ. On its inner and outer sides the cells of the organ progressively merge with those of the general chitogenous epithe- lium (Fig. 5, ), of which they are specialized portions. The thickening of the integument already mentioned is lens-like in section. It shows two clearly defined layers of equal thickness, the outer of which is closely striated, and the inner only slightly so. These layers are not distinguishable in the much thinner chitin lining the branchial chamber, although this may be merely on account of its delicacy.
Size: 1933px × 1035px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
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