DNA barcoding the phyllosoma of Scyllarides squammosus (H. Milne Edwards, 1837) (Decapoda: Achelata: Scyllaridae)

Checklist of decapod crustaceans from the coast of the São Paulo state (Brazil) supported by integrative molecular and morphological data: V. Dendrobranchiata and Pleocyemata [Achelata, Astacidea, Axiidea, Caridea (Alpheoidea and Processoidea excluded), Gebiidea, Stenopodidea]

This checklist is the fifth and last compilation on the decapod crustaceans reported to São Paulo (Brazil) coastal area, resulting from long-term multidisciplinary projects, which combined morphological analyses and molecular techniques. The current research includes 75 decapod species, herein referred as shrimps/lobsters-like (shrimps, ghost-shrimps, lobsters, and related groups), reported to São Paulo coastal area. These species occur in marine, estuarine, and amphidromous habitats and are classified into 21 families as follow: Aristeidae (2 spp., 2 genera), Atyidae (4 spp., 2 genera), Axianassidae (1 sp., 1 genus), Callianassidae (1 sp., 1 genus), Callichiridae (6 spp., 4 genera), Crangonidae (1 sp., 1 genus), Glyphocrangonidae (1 sp., 1 genus), Luciferidae (2 spp., 2 genera), Nephropidae (4 spp., 2 genera), Palaemonidae (15 spp., 9 genera), Palinuridae (2 spp., 1 genus), Pandalidae (1 sp., 1 genus), Pasiphaeidae (1 sp., 1 genus), Penaeidae (10 spp., 6 genera), Sergestidae (3 spp., 3 genera), Sicyoniidae (4 spp., 1 genus), Scyllaridae (5 spp., 3 genera), Solenoceridae (4 spp., 3 genera), Stenopodidae (2 spp., 1 genus), and Upogebiidae (6 spp., 1 genus). We generated new sequences of cytochrome oxidase subunit I (barcode region) and 16S genes (51 and 54, respectively) of 54 species. Our examination concluded that 75 shrimps/lobsters-like species are reported to the São Paulo coast. We excluded Leander tenuicornis (Palaemonidae), Penaeus setiferus (Penaeidae), Philocheras gorei (Crangonidae), and Rhynchocinetes typus (Rhynchocinetidae) from this list.  

DNA barcoding allows identification of undescribed crab megalopas from the open sea

Megalopas of 15 brachyuran crab species collected in the open sea plankton, and unknown until now, were identified using DNA barcodes (COI and 16S rRNA). Specimens belonging to the families Portunidae, Pseudorhombilidae and Xanthidae (Crustacea, Decapoda, Brachyura), and corresponding to the species Achelous floridanus, Arenaeus mexicanus, Callinectes amnicola, C. arcuatus, C. ornatus, C. toxones, Charybdis (Charybdis) hellerii, Portunus hastatus, Thalamita admete, Scopolius nuttingi, Etisus odhneri, Liomera cinctimanus, Neoliomera cerasinus, Pseudoliomera variolosa, and Williamstimpsonia stimpsoni, are described and illustrated, and compared with other congeneric species previously described. We also provide a new geographical record for N. cerasinus and the most remarkable features for each species.

The complete mitochondrial genome of Aesop slipper lobster Scyllarides haanii (De Haan, 1841)

The complete mitochondrial genome of Scyllarides haanii from South China Sea was first determined and characterized. With a length of 15,666 bp, the circular mitogenome of S. haanii consists of 22 tRNA genes, two rRNA genes, 13 protein-coding genes (PCGs), and one control region. The nucleotide composition is significantly biased (A, G, T, and C was 32.05%, 12.45%, 33.97%, and 21.53%, respectively) with A + T contents of 66.02%. Two PCGs used an unusual initiation codon, and five PCGs were ended with an uncomplete or abnormal stop codon. One microsatellite was identified in the mitogenome located in ND4 gene. Phylogenetic analysis demonstrated that S. haanii was first clustered with Scyllarides squammosus, then together with Scyllarides latus.

Complete mitochondrial genome of blunt slipper lobsters Scyllarides squammosus (H. Milne Edwards, 1837)

The complete mitochondrial genome of Scyllarides squammosus was first determined and characterized. With a length of 15,644 bp, it consists of 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes (PCGs), and 1 control region. The nucleotide composition is significantly biased with AT contents of 65.6%. Among these PCGs, five of them used an unusual initiation codon, and nine genes ended with an incomplete or abnormal stop codon. Two microsatellites were identified and located in COX3 gene and D-loop region. Phylogenetic analysis demonstrated that S. squammosus was first clustered with Scyllarides latus, which was consistent with the previous work.

The design and testing of mini-barcode markers in marine lobsters

Full-length mitochondrial cytochrome c oxidase I (COI) sequence information from lobster phyllosoma larvae can be difficult to obtain when DNA is degraded or fragmented. Primers that amplify smaller fragments are also more useful in metabarcoding studies. In this study, we developed and tested a method to design a taxon-specific mini-barcode primer set for marine lobsters. The shortest, most informative portion of the COI gene region was identified in silico, and a DNA barcode gap analysis was performed to assess its reliability as species diagnostic marker. Primers were designed, and cross-species amplification success was tested on DNA extracted from a taxonomic range of spiny-, clawed-, slipper- and blind lobsters. The mini-barcode primers successfully amplified both adult and phyllosoma COI fragments, and were able to successfully delimit all species analyzed. Previously published universal primer sets were also tested and sometimes failed to amplify COI from phyllosoma samples. The newly designed taxon-specific mini-barcode primers will increase the success rate of species identification in bulk environmental samples and add to the growing DNA metabarcoding toolkit.