No abstract

Species level identifications of morphologically simple marine algae have undoubtedly caused biodiversity assessments to be an arduous task. The green algal genus Ulva L., 1753, is notorious for morphological plasticity and cryptic speciation. We used two chloroplast-encoded (rbcL and tufA) molecular markers and the nuclear internal transcribed spacer 1 (ITS1) of the ribosomal cistron to detect Ulva ohnoi M. Hiraoka and S. Shimada, 2004, a species known for forming green tides in Japan, as a new record for the Western Atlantic, including the Gulf of Mexico (GoMX) and Atlantic coast of Florida. All rbcL sequences from this investigation were identical to reports for U. ohnoi. The Western Atlantic isolates showed relatively low genetic diversity in tufA and ITS1 sequences, which suggests that this species is not native to the GoMX and Atlantic Florida. Furthermore, we have identified U. ohnoi as the species that formed an ephemeral, localized overgrowth during July of 2013 in Biscayne Bay, Florida, an area with a persistent bloom of two other green algal species, Anadyomene stellata J. V. Lamouroux, 1812, and Anadyomene sp., due to eutrophication from anthropogenic nutrient loading near canals. A tissue nutrient analysis of samples from this overgrowth of Ulva showed that this species has a high affinity for nitrogen, especially ∂15N, which suggests anthropogenic sources of N. Further investigations are needed to assess the geographical ranges of this species in this region as well as the potential invasiveness of this alga in the Western Atlantic. It is highly recommended to monitor the abundance of this species in response to nutrient discharges in Biscayne Bay.

Aglajidae is a family of tropical and temperate marine Cephalaspidea gastropod slugs regarded as active predators. In order to better understand their food habits and trophic interactions, we have studied the diet of all genera through the examination of gut contents. Specimens were dissected for the digestive tract and gut contents were removed and identified by optical and scanning electron microscopy. Our results confirmed that carnivory is the only feeding mode in aglajids and showed a sharp preference for vagile prey (94% of food items). We suggest that the interaction between crawling speed, presence of sensorial structures capable of detecting chemical signals from prey, and unique features of the digestive system (e.g. lack of radula, eversion of the buccal bulb, thickening of gizzard walls) led aglajid slugs to occupy a unique trophic niche among cephalaspideans, supporting the hypothesis that dietary specialization played a major role in the adaptive radiation of Cephalaspidea gastropods.

In this reply, we address the criticism directed recently to our work by Galil et al. (2016) dismissing the hypothesis that the Suez Canal can act as a revolving door allowing marine species to move both ways between the Red Sea and the Mediterranean Sea. We reiterate that the presence in the Red Sea of the Indo-West Pacific sea slug Chelidonura fulvipunctata Baba, 1938 is most parsimoniously explained by an invasion from the Mediterranean and highlight several recent studies combing morphology and molecular phylogenetics where established views about the presence of alien Indo-Pacific / Red Sea species in the Mediterranean were proven wrong. Caution is suggested when assuming the conspecificity of species between these realms based solely on external features.

total de 21 especies agrupadas en 13 géneros y 10 familias han sido identifi cadas y registradas para los estados