P.J. Krug's research while affiliated with California State University, Los Angeles and other places

Publications (169)

Article
Host shifting in insect-plant systems was historically important to the development of ecological speciation theory, yet surprisingly few studies have examined whether host shifting drives diversification of marine herbivores. When small-bodied consumers feed and also mate on a preferred host, disruptive selection can split a population into host r...
Article
Transitions to terrestriality have been associated with major animal radiations including land snails and slugs in Stylommatophora (>20 000 described species), the most successful lineage of ‘pulmonates’ (a non-monophyletic assemblage of air-breathing gastropods). However, phylogenomic studies have failed to robustly resolve relationships among tra...
Article
Full-text available
The genus Thuridilla Bergh, 1872 comprises mostly tropical sap‐sucking sea slugs species with flamboyantly coloured forms. However, the potential for cryptic or pseudocryptic species masked by convergent or polymorphic colour patterns has not been tested using molecular characters. In this study, we sampled 20 of the 23 recognized worldwide species...
Article
Insight into how coastal organisms will respond to changing temperature and salinity regimes may be derived from studies of adaptation to fluctuating estuarine environments, especially under stressful range-edge conditions. We characterized a dynamic range boundary between two estuarine sea slugs, Alderia modesta (distributed across the North Pacif...
Article
Full-text available
Complex polyketides are typically associated with microbial metabolism. Here, we report that animals also make complex, microbe-like polyketides. We show there is a widespread branch of fatty acid synthase- (FAS)-like polyketide synthase (PKS) proteins, which sacoglossan animals use to synthesize complex products. The purified sacogolassan protein...
Preprint
Full-text available
Animals are rich sources of complex polyketides, including pharmaceuticals, cosmetics, and other products. Most polyketides are associated with microbial or plant metabolism. For this reason, symbiotic bacteria or dietary organisms are often the true producers of compounds found in animals. Although increasing evidence suggests that animals themsel...
Article
Nearly all of the recognized species of sea slugs in clade Sacoglossa (about 300 taxa) are herbivorous, using a uniseriate radula in suctorial feeding. The only exceptions are a pair of monotypic genera in the ceratiform family Limapontiidae: Olea Agersborg, 1923 from the northeastern Pacific, and Calliopaea d'Orbigny, 1837 from the northeastern At...
Article
“Cryptic” can refer to species that match their background through camouflage or disruptive colouration, or in taxonomy to externally similar but unrecognized congeners. In adaptive resemblance, organisms resemble parts of a larger host animal or plant on which the mimic is highly cryptic. Mimetic lineages that radiate onto superficially similar ho...
Article
Polybranchia Pease, 1860 is a tropical and subtropical genus of sacoglossan heterobranch sea slugs. Eight nominal species of Polybranchia have been described; however, the taxonomic status of most species is uncertain. Here, we present an integrative assessment of species diversity in Polybranchia. Two methods of molecular species delimitation supp...
Data
Photo of Elysia cf. tomentosa sp. 5 collected by Omid Alizadeh in association with the seaweed, Caulerpa sertularioides, in the northern Persian Gulf (Bandar Abbas, Iran)
Data
Table S1- Provisional identifications, sample codes, collection details and NCBI accession numbers for specimens used in "Molecular confirmation of the occurrence of Elysia cf. tomentosa (Mollusca: Heterobranchia) in the Persian Gulf".
Article
The molluscan fauna of the Persian Gulf has recently been relatively well documented, yet there are few records of heterobranch sea slugs (opisthobranchs) from the Arabian parts and no report from the Iranian waters. Here we report for the first time the occurrence of one of these molluscs in the northern Persian Gulf (Bandar Abbas, Iran). Sacoglos...
Article
Predicting biotic resistance to highly invasive strains of "killer algae" (Caulerpa spp.) requires understanding the diversity and feeding preferences of native consumers, including sea slugs in family Oxynoidae. Past studies reported low algal host specificity for Oxynoe (6 spp.) and Lobiger (4 spp.), but these taxonomically challenging slugs may...
Article
An integrative approach to investigate the species-level diversity in Oxynoe (Mollusca, Heterobranchia, Sacoglossa) revealed the existence of 11 distinct taxa. Oxynoe viridis (Pease, 1861) and Oxynoe antillarum Mörch, 1863 are redescribed Oxynoe natalensis E. A. Smith, 1903 and Oxynoe azuropunctata Jensen, 1980 are regarded as valid. Species origin...
Article
Placida cremoniana (Trinchese, 1892) is a sacoglossan heterobranch sea slug of striking coloration, with a reported range that has increased dramatically in recent years. Described from the Mediterranean in 1892, nominal conspecifics were reported from Japan in 1959, and since the 1990s, additional populations have been reported from across the tro...
Article
Full-text available
The Caribbean is a biodiversity hotspot for photosynthetic sea slugs, with about 27 described species in the genus Elysia Risso, 1818. However, many species are poorly known or have complex taxonomic histories, complicating assessments of regional biodiversity and impeding studies of plastid symbiosis, speciation, and larval biology. Using an integ...
Article
Full-text available
Background: The Bocas del Toro Archipelago is located off the Caribbean coast of Panama. Until now, only 19 species of heterobranch sea slugs have been formally reported from this area; this number constitutes a fraction of total diversity in the Caribbean region. Results: Based on newly conducted fieldwork, we increase the number of recorded hete...
Article
Population-level consequences of dispersal ability remain poorly understood, especially for marine animals in which dispersal is typically considered a species-level trait governed by oceanographic transport of microscopic larvae. Transitions from dispersive (planktotrophic) to non-dispersive, aplanktonic larvae are predicted to reduce connectivity...
Article
Full-text available
For 40 years, paleontological studies of marine gastropods have suggested that species selection favors lineages with short-lived (lecithotrophic) larvae, which are less dispersive than long-lived (planktotrophic) larvae. Although lecithotrophs appeared to speciate more often and accumulate over time in some groups, lecithotrophy also increased ext...
Article
Full-text available
The history of the genus Costasiella is summarized. A new species of Costasiella, C. arenaria n. sp., from Lake Worth, Florida, USA is described. For comparative purposes specimens of C. formicaria (Baba, 1959) from Japan and serial sections of C. pallida Jensen, 1985 from Hong Kong have also been examined. These three species, like the type specie...
Article
Pulmonates, with over 30,000 described species, represent the largest radiation of non-marine animals outside of Arthropoda. The pulmonate lung was a key evolutionary innovation enabling diversification of terrestrial and freshwater snails and slugs. However, recent studies drew conflicting conclusions about pulmonate monophyly, and support for a s...
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##
Data
##Assembly-Data-START## Assembly Method :: Geneious v. 5.1.4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##