A New Species of Mullet Chelon caeruleum (Family: Mugilidae) with Description of its Genetic Relationship to Some Mugilids

摘要

Chelon caeruleum sp. nov. is described as a new species of Chelon encountered in the Rashid coastal region of the Mediterranean Sea, Egypt. With this finding, the new species is the sixth member of the genus Chelon. Chelon caeruleum sp. nov. is distinguished from its congeners by the following characters: colouration of body is dark bluish grey dorsally and the sides are blue; head length 20.5 to 21.6% SL; head width 13 to 13.5% SL; pre-first dorsal fin length 50% SL; eye diameter 4.6 to 5.2% SL; postorbital length 10.7 to 11.1% SL; unbranched pyloric caeca are 2 short and 4 long; a pair of long (one longer than the other), spine-like neural postzygapophyse on the second vertebra. DNA of Chelon caeruleum sp. nov. and five mullet species (Mugil cephalus, Liza carinata, Liza ramada, Liza aurata, and Chelon labrosus) was extracted then amplified using polymerase chain reaction (PCR) and sequenced. The mtDNA cytochrome oxidase subunit I sequence analysis confirmed that Chelon caeruleum sp. nov. is distinct from other congeners of Chelon and it is a different species of Chelon which is new to science.