A crab with three eyes, two rostra, and a dorsal antenna-like structure

作者：Scholtz Gerhard^*; Ng Peter K L; Moore Stephen

来源：Arthropod Structure & Development, 2014, 43(2): 163-173.

DOI：10.1016/j.asd.2013.10.007

• Crustacea Decapoda
• Siamese twins
• Regeneration
• Brain
• Development

We describe a malformed specimen of the freshwater crab Amarinus locusts-is from New Zealand. With three eyes in a horizontal row, two rostra, and a dorsal antenna-like structure, the pattern of malformation of this animal is unique and has not been described before. A careful inspection and description of external and internal structures, in particular the central nervous system, were carried out. These revealed, in addition to the external abnormalities, a retarded brain with a hypertrophied and backwards bent protocerebrum connected with all three eyes and putatively with the dorsal antenna-like structure. Based on these data, a variety of hypotheses about the causes for this kind of malformation are discussed. A scenario combining a conjoined twin (Duplicitas anterior) based on the duplication of the embryonic anterior head lobes and a regeneration event leading to the replacement of an eye by an antenna shows the best fit to the observed patterns.

• 出版日期2014-3