First record of a Lessepsian migrant: the sea cucumber Holothuria (Theelothuria) hamata Pearson, 1913.

First record of a Lessepsian migrant: the sea cucumber Holothuria (Theelothuria) hamata Pearson, 1913. A single specimen of the Indo-West Pacific sea cucumber Holothuria (Theelothuria) hamata Pearson, 1913 has been captured in 2017 in the Mediterranean Sea, Turkey, Iskenderun Bay, at 30 m depth. This specimen is here described, and the taxonomy of the species is briefly discussed. Despite the lack of timed biogeographic evidence, we here argue that H. hamata is a Lessepsian migrant; the first in its genus and only the second holothuroid.

Systematics of Scorpaeniformes species in the Mediterranean Sea inferred from mitochondrial 16S rDNA sequence and morphological data.

Genetic and morphological divergence and phylogenetic relationships of Scorpaeniformes fish including two genera and six species, Helicolenus dactylopterus, Scorpaena maderensis, Scorpaena porcus, Scorpaena elongata, Scorpaena scrofa, Scorpaena notata, living in the Mediterranean Sea, were investigated with morphological and mitochondrial 16S rDNA sequence data. The mean nucleotide diversity was found to be 0.0792. Average sequence divergence between species of Sebastidae and Scorpaenidae was 8.4%, and 6.4%. between species of the genus Scorpaena. For congeneric comparisions, the lowest genetic divergence (0.7%) was observed between S. porcus and S. notata, and the highest divergence (10.8%) was detected between S. maderensis and S. notata. High levels of nucleotide divergence were detected between species of two families, and the maximum value was found to be 14.5% between H. dactylopterus and S. elongata. The two phylogenetic methods (NJ and MP) identified two major lineages. In the NJ tree S. elongata was the sister group to S. scrofa. S. maderensis was more divergent from these groups. Another lineage contained S. porcus and S. notata. The topology of the MP tree is similar to that of the NJ tree. The pattern and degree of morphological differentiation was not congruent with the genetic differentiation. The Euclidiean distances of morphological data revealed very high morphological divergence between the two families. The highest morphological divergence was observed between H. dactylopterus and S. porcus, and the lowest was detected between S. elongata and S. notata. The present genetic and morphological data support the present monophyletic status of the Scorpaena genus.