Reproductive Traits of Red Lionfish, Pterois volitans, at Two Sites Off the Northern Coast of the Yucatan Peninsula, Mexico

The Red lionfish Pterois volitans was introduced into the western Atlantic Ocean more than 30 years ago, but in the Gulf of Mexico it was first recorded in 2010. Given its population spread in the region, the lionfish has become a biological invasion that threatens the marine ecosystem. The objective of this work was to describe some basic reproductive traits of this fish for the first time in the southern gulf, off the northern coast of the Yucatan Peninsula, Mexico. Samples were collected as part of a citizen-science program, in which lobster diver-fishers speared lionfish between 2010 and 2018. Lionfish's length-frequency distribution was significantly different between sexes, with males larger than females. Sex ratio showed a significant predominance for males. Histological analysis revealed the smallest mature female and male were 160 mm TL and 196 mm TL, respectively. Females achieved 50% sexual maturity at a slightly smaller size compared to that of males. Both sexes were in the spawning capable phase during all months sampled (June to December), with female gonadosomatic index peaking in June, September and December. Spawning interval is estimated to be every four days. In the southern gulf, lionfish mature at a larger size than that from both the northern gulf, and other invaded regions in the western Atlantic Ocean, with the exception of Bermuda. Although sample size in our study is limited, the opportunity to identify a maturation size is helpful to establish a baseline for lionfish life history in the southern gulf.