Biology subjects

Siccha-Ramirez, R.

Publications and source records attributed to Siccha-Ramirez, R..

2 recordsLinked to original sources

bioRxiv2025

Geographical variation in mitogenomes of the largetooth sawfish Pristis pristis: challenges and perspectives for conservation efforts

Sawfishes (Pristidae) have been severely impacted by coastal development and unregulated fisheries and are considered Critically Endangered by the IUCN Red List. Environmental DNA (eDNA) analyses have shown potential for monitoring elasmobranch species, with various studies focusing on using species-specific approaches to detect Pristis species. However positive detection using existing probes has not been confirmed in some geographic regions where they would be expected. Here, we aimed to test whether mutations at key sites have been detrimental to species-specific detection of P. pristis (Linnaeus, 1758) using the existing probe set. To test this hypothesis mitogenomes were assembled that were found to follow the typical pattern of vertebrate mitogenomic organization. Phylogenetic trees showed similar topologies and confirmed geographic mitochondrial variation in P. pristis. Mismatches for the published 12S species-specific probe set for P. pristis were identified that prevent amplification of positive control samples from Brazil. However, ddPCR detection of the positive control was possible using a newly designed species-specific probe set. This study highlights how geographical variation can severely impact the success of generally applying species-specific detection systems developed based on data from only one geographical region. The new mitogenomes and species-specific probe set developed here may also contribute to improving the potential to map and monitor these Critically Endangered species across the globe. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/639618v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@1fb30fborg.highwire.dtl.DTLVardef@4cd3a8org.highwire.dtl.DTLVardef@1dbd985org.highwire.dtl.DTLVardef@a5d7d3_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO C_FIG

ecology↗

bioRxiv2024

Phylogeography of the electric rays of the family Narcinidae (Gill, 1862): systematic review and evidence of the dispersal routes to America.

The electric rays belonging family Narcinidae are a cosmopolitan group, which has come under increasing scrutiny in relation to the taxonomic composition of the family and its phylogenetic position within the order Torpediniformes. Phylogeographic inferences can provide important insights into the present-day distribution of the narcinid species, as well as the systematics of the group. In this context, the present study evaluates the evolutionary and biogeographic history of the family Narcinidae, inferring distribution patterns and the molecular systematics of these organisms based on the DNA barcode. The results of the analysis indicate that the electric rays originated in the Central Indo-Pacific realm, with all other dispersal events beginning from this region. Two different dispersal routes were observed for the American narcinids. The first route was from the Central Indo-Pacific realm to the Pacific Ocean and then the Caribbean Sea, prior to the closure of the Isthmus of Panama. The second route start on Central Indo-Pacific realm passed South Africa continent before crossing the Atlantic. The principal torpediniform lineages diversified between the end of the Cretaceous and the early Paleocene, with the present-day narcinid taxa arising and diversifying between 25 and 20 Mya. The present study confirms the lack of monophyly in the Narcinidae, validates the genus Narcinops, and restricts the occurrence of the genus Narcine to the coastal environments of the Americas, which emphasizes the need for the review and revalidation of the synonym Syrraxis for the narcinids of the Central/Western Indo-Pacific realm. This study also describes additional lineages for Narcine entemedor and Narcine maculata and validates the occurrence of three species (Narcinesp., Narcine brasiliensis, and Narcine bancroftii) in the Atlantic Ocean, based on the published data, and emphasizes the need for a definitive description of Narcine sp.

evolutionary biology↗