Genetic-variability
Guides
Petrolisthes armatus
Green Porcelain Crab
Petrolisthes armatus, commonly known as the green porcelain crab, is a small porcellanid crab native to the southwestern Atlantic, particularly Brazil. The species has established invasive populations along the southeastern United States coast, where densities can exceed 30,000 individuals per square meter. Genetic studies confirm it as a single monophyletic species with exceptional geographic range spanning the Atlantic and eastern Pacific. It is frequently parasitized by the bopyrid isopod Aporobopyrus curtatus, which causes parasitic castration.
invasive-speciesfilter-feederparasite-hostintertidalporcelain-craboyster-reefsymbiosisplanktonic-larvaevisual-ecologycrustaceandecapodanomuraporcellanidaesouthwestern-atlanticeastern-pacificsoutheastern-united-statesbopyrid-parasiteAporobopyrus-curtatusestuarinemangrovesponge-symbiosisgaze-stabilizationachromatic-visionlarval-transportoyster-bedballast-wateraquaculturemonophyleticcryptic-species-complexparasitic-castrationzoeamegalopapleopodspermatophorechellipedcarapacegranulatedolive-greenblue-colorationFarol-IslandBrazilGeorgiaSouth-CarolinaFloridaPanamaCosta-RicaEcuadorPeruBaja-CaliforniaCaribbeanGulf-of-MexicoWest-IndiesAscension-IslandBermudaBahamasWest-Africarock-rubblesoft-sedimentshallow-subtidallower-intertidaldensity-30000-per-square-meter6-8-mm0.5-gorange-spotfour-segmented-chelipedantennae-outside-eyesvestigial-fourth-leg-pairfeathery-mouthpartszooplanktonscavengerpheromone-settlement-cue3-mm-sexual-maturity17%-parasite-prevalencebranchial-chamber-parasitesynchronous-growth-parasite-hostcastrationvisual-noisecaustic-flickerpolarization-sensitivityoptomotor-assaytidal-creekspectrally-narrow-environmentmitochondrial-DNAgenetic-variabilityexceptional-rangepre-Canal-Panama18591930s-Floridalineagewarm-temperate-Atlanticspecies-complexhalf-crabsquat-lobster-relativetrue-crabfalse-crabDecapodaMalacostracaArthropodaCrustaceaGibbes-1850Porcellana-armatagreen-porcelain-crabPetrolisthes-armatusSpeyeria mormonia
Mormon fritillary
Speyeria mormonia, commonly known as the Mormon fritillary, is a small montane butterfly distributed across western North America from the Yukon to California and Nevada. The species exhibits extreme protandry, with males emerging at least two weeks before females, leading to skewed adult sex ratios toward males. It occupies diverse habitats including rocky mountainsides, meadows, grasslands, and forest clearings, with populations typically occurring in small, semi-isolated patches. Multiple subspecies have been described, reflecting the species' broad geographic range and high genetic variability.