Essential oils from Cymbopogon citratus and Lippia sidoides in the anesthetic induction and transport of ornamental fish Pterophyllum scalare

This study verified the effects of essential oils from Lippia sidoides (EOLS) and Cymbopogon citratus (EOCC) on the anesthesia of freshwater angelfish (Pterophyllum scalare) of two different sizes (juveniles I (0.82 g) and II (2.40 g)) and the transport (8 h) of juveniles II. Fish were exposed to different concentrations of EOLS and EOCC: 0, 10, 25, 50, 75, 100, 150, 200, and 250 mg L^-1. Ventilatory rate (VR) and transport for 8 h with 0, 10, and 15 mg L^-1 of each essential oil were evaluated in juveniles II. The major components found in EOLS and EOCC were carvacrol (44.50%) and α-citral (73.56%), respectively. The best sedation and anesthesia times for both essential oils were obtained with 10 and 25 mg L^-1 and 200 and 250 mg L^-1 for juveniles I and II, respectively. Fish sedated with EOLS had lower VR values than the other treatments. Blood glucose levels were higher in ornamental fish transported with 10 and 15 mg EOLS L^-1 and 15 mg EOCC L^-1. Hepatic glycogen values were higher in the control group. In general, fish transported with 10 mg EOLS L^-1 showed fewer gill histological alterations than other transported fish. When the type of lesion was evaluated, the highest gill alterations occurred in fish transported with EOCC. In conclusion, 10 mg EOLS L^-1 could be used to transport of juveniles II because although this concentration increased blood glucose levels, it decreased the VR and muscle glycogen levels and caused only mild alterations to the gills.

The complete mitochondrial genome sequence of Pterophyllum scalare (Cichliformes: Cichlidae)

Pterophyllum scalare belongs in the family Cichlidae of Cichliformes. This species and its congeners are characterized by a compressed and disc-shaped body with dorsal and anal spiny rays increasing in length from anterior to posterior part of the fin. In this study, we determine and describe the complete mitogenome sequence of Pterophyllum scalare for the first time, which is 16,494 bp in length, and contains 37 genes, including 13 protein-coding genes, 2 rRNAs, 22 tRNAs, 1 origin of replication on the light-strand (OL) and a putative control region. The overall base composition is 27.5% A, 26.8% T, 30.1% C and 15.6% G, with a slight AT bias (54.3%). All protein-coding genes share the start codon ATG, except for COI that begins with GTG. These results are expected to provide useful molecular data for phylogenetic studies of Cichlidae and Cichliformes. Maximum Likelihood (ML) tree and Bayesian analyses based on partitioned nucleotide sequences of 12 mitochondrial protein-coding genes were constructed and both yielded trees with identical topologies.