The razor clam Solen marginatus has a diploid chromosome number of 38. The karyotype consists of one metacentric/submetacentric, three submetacentric/metacentric, five submetacentric, one submetacentric/subtelocentric, one subtelocentric/submetacentric, six subtelocentric and two telocentric chromosome pairs. Staining with chromomycin A3 revealed bright positive bands subcentromerically in the long arms of one medium-sized subtelocentric pair, while DAPI staining showed uniform fluorescence in all chromosomes of the complement. Fluorescence in situ hybridization using an 18S-5.8S-28S rDNA probe locates these loci at the subcentromeric region of one subtelocentric pair and at the subtelomeric region of another subtelocentric pair.   

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