Calibration of nucleotide sequence divergence rates provides an important method by which to test many hypotheses evolution. In the absence adequate fossil record, geological events, rather than first appearances sister taxa in are often used calibrate molecular clocks. The formation Isthmus Panama, isolated tropical western Atlantic and eastern Pacific oceans, is one such event that frequently infer divergence. Isthmian calibrations assume morphologically similar "geminate" species living...

Abstract In marine environments, many species have apparently colonized high latitude regions following the last glacial maximum (LGM) yet lack a life‐history stage, such as free‐living larva, that is clearly capable of long‐distance dispersal. Two hypotheses can explain modern distributions these taxa: (1) survival in northern refugia during LGM or (2) rapid post‐glacial dispersal by nonlarval stages. To distinguish two scenarios, I characterized genetic structure closely related...

Approximately 20,000 years ago the last glacial maximum (LGM) radically altered distributions of many Northern Hemisphere terrestrial organisms. Fewer studies describing biogeographic responses marine species to LGM have been conducted, but existing genetic data from coastal indicate that fewer taxa show clear signatures post-LGM recolonization. We assembled a mitochondrial DNA (mtDNA) set for 14 co-distributed northeastern Pacific rocky-shore four phyla by combining new sequences ten with...

Cytochrome P450s (CYPs) in animals fall into two categories: those that synthesize or metabolize endogenous molecules and interact with exogenous chemicals from the diet environment. The latter form a critical component of detoxification systems. Data mining manual curation Daphnia pulex genome identified 75 functional CYP genes, three pseudogenes. These CYPs belong to 4 clans, 13 families, 19 subfamilies. 2, 3, 4, mitochondrial clans are same four found other sequenced protostome genomes....

Two recently diverged northeastern Pacific sibling snail species, Nucella ostrina and N. emarginata, currently inhabit adjacent zoogeographic provinces. Their distributions overlap in central California to the north of a major faunal boundary at Point Conception, (PC). To test hypothesis that modern sympatry is due recent northward range expansion by I analyzed population structures both species with nuclear (allozyme) mitochondrial DNA (mtDNA) markers. Populations emarginata region exhibit...

Genetic diversity (θ), effective population size (Ne), and contemporary levels of gene flow are important parameters to estimate for species conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed demographic history S. lewini across its Eastern Pacific (EP) range by applying classical coalescent genetic methods a combination 15 microsatellite loci mtDNA control region sequences. In addition significant structure...

Abstract Coral reefs support the most diverse assemblages of marine life on Earth, yet are declining due to local and global stressors. Rapid widespread monitoring is essential for tracking ecosystem responses, but assessment coral communities traditionally relies time‐consuming visual estimates cover, percentage substrate occupied by living corals. The analysis environmental DNA (eDNA) offers fast efficient insights into abundance distribution species, it remains untested monitor biomass....

Early detection of nuisance species is crucial for managing threatened ecosystems and preventing widespread establishment. Environmental DNA (eDNA) data can increase the sensitivity biomonitoring programs, often at minimal cost effort. However, eDNA analyses are prone to errors that complicate their use in management frameworks. To address this, studies must consider imperfect detections estimate error rates. Detecting low abundances with uncertainty vital successful containment eradication....

Abstract Coalescent samplers are computational time machines for inferring the historical demographic genetic processes that have given rise to observable patterns of spatial variation among contemporary populations. We used traditional characterizations population structure and coalescent‐based inferences about reconstruct histories two co‐distributed marine species, frilled dog whelk, Nucella lamellosa , bat star, Patiria miniata . Analyses were consistent with previous work in both...

Abstract Aim The rise of the Isthmus Panama and formation ‘geminate’ species pairs serves as an important model allopatric speciation. However, to function a system, hypothesized geminates must first be shown each other’s closest living relatives. If presence cryptic taxa obscures true relationships, biogeographical histories transisthmian are likely misinterpreted. We have therefore completed phylogeographic survey bivalve subgenus Acar in genus Barbatia characterize patterns tropical...

Seafood mislabeling distorts the true abundance of fish in sea, defrauds consumers, and can also cause unwanted exposure to harmful pollutants. By combining genetic data with analyses total mercury content, we have investigated how species substitutions fishery-stock obscure contamination Patagonian toothfish (Dissostichus eleginoides), known as “Chilean sea bass”. show wide variation concentrations such that consumers may be exposed either acceptable or unacceptable levels depending on...

Abstract Ecological patterns in biodiversity are primarily based on conspicuous organisms. Few methods used to survey the taxonomically rich cryptobiome, which is made up of inhabitants from within microhabitats. One way that cryptic marine can be non‐invasively surveyed by analyzing environmental DNA (eDNA) present seawater. Using coral reefs as a model system, here we compare estimates diversity among community biomass and eDNA metabarcoding sampling with broad eukaryotic marker (COI)....

Laboratory experiments revealed that the rocky shore gastropod, Nucella lamellosa (Gmelin), could discriminate between effluents of predatory and non-predatory crabs. N. turned away from seawater had passed over large crab, Cancer productus Randall. This avoidance behavior was observed in snails two localities that, based on differences shell form, presumably experienced different levels predation intensity. The scent crabs Pugettia producta (Randall) Lopholithodes mandtii Brandt no effect...

The identification of effective, nontoxic means for physically marking and tracking marine invertebrate larvae is a necessary step towards meeting major goal modern population biology, the direct measurement larval dispersal. An inexpensive, rapid effective bivalve would be particularly useful because, as taxonomic group, bivalves contain many commercially important exploited species. Likewise, produce large numbers propagules experimental procedures and, species, methods rearing have been...

Despite the importance of Nucella as a model system in numerous fields biology, no phylogenetic analysis genus, including every widely recognized species, has been conducted. We have analysed about 4,500 bp DNA from six different genes (three mitochondrial, three nuclear) each taxon genus. Our results showed western Pacific N. heyseana and freycinetii distinct distantly related, but found evidence that elongata is heyseana. also resolved closest living relative North Atlantic lapillus and,...

The European eel ( Anguilla anguilla ) has declined by over 90% since the early 1980s and been listed as critically endangered. Yet, despite strict export bans from Union, is still sold illegally in many countries. Efforts to monitor trade of eels have primarily concentrated Asian markets where concerningly high rates reported. Comparably fewer studies assessed identities samples United States (US), obvious implications for conservation. To address this knowledge gap, we purchased 137...

Geminate species are morphologically similar sister-species found on either side of the Isthmus Panama. The existence all geminates in tropical Eastern Pacific ocean and Caribbean Sea is most often explained by vicariance: closure Central American Seaway 3.1 to 3.5 Ma simultaneously isolated populations with amphi-American distributions. In this paper, we test potential morphological measurements for discriminating between Recent geminate pairs from three genera (Arca, Arcopsis, Barbatia)...