On some deep-sea Stenheliinae from the Gulf of California and the west coast of the Baja California Peninsula (Mexico): Wellstenhelia euterpoides sp. nov., and Wellstenvalia wellsi gen. et sp. nov. (Copepoda: Harpacticoida: Miraciidae)

At present, only 11 species of harpacticoid copepods have been described from the deep sea of the Gulf of California and the west coast of the Baja California Peninsula. These efforts had until recently been focused exclusively on the families Ameiridae Boeck, Argestidae Por, and Rhizothrichidae Por. Preliminary analyses revealed also an important contribution of the subfamily Stenheliinae Brady (Miraciidae Dana) to the overall species richness and diversity of deep-sea benthic copepods from the west coast of the Baja California Peninsula, and the central and southern Gulf of California. One new species of the genus Wellstenhelia Karanovic & Kim, 2014, We. euterpoides sp. nov., and one new genus and species, Wellstenvalia wellsi gen. et sp. nov., are herein described from sediment samples taken at eight sampling stations in the west coast of the Baja California Peninsula and in the central and southern Gulf of California. Wellstenhelia euterpoides sp. nov. seems to be closely related to We. euterpe Karanovic & Kim, 2014 with which it shares the reduced armature complement of the baseoendopod of the female fifth leg. The so far monotypic genus Wellstenvalia gen. nov. was found to be closely related to Muohuysia Özdikmen, 2009 and Wellstenhelia. Some comments on the relationships between the new genus proposed here and other stenheliin genera and species are provided as a contribution towards the monophyly of the subfamily.

On some deep-sea Stenheliinae from the Gulf of California and the west coast of the Baja California Peninsula (Mexico): Pseudostenhelia bathyalis sp. nov., and Beatricella calidafornax sp. nov. (Copepoda: Harpacticoida: Miraciidae)

At present, only a handful of harpacticoid species of the families Ameiridae Boeck, Ancorabolidae Sars, Argestidae Por, and Rhizothrichidae Por have been described from the deep sea of the Gulf of California and west coast of the Baja California Peninsula. Recent efforts resulted in the description of a new genus, Wellstenvalia Gómez & Cruz-Barraza, 2021, closely related to Muohuysia Özdikmen, 2009 and Wellstenhelia Karanovic & Kim, 2014 and some new deep-sea species of Delavalia Brady, 1869. Other new stenheliin genera from the Gulf of California and the west coast of the Baja California Peninsula are the subjects of another contribution in this volume. The present contribution deals with the description of the first deep-sea representatives of Pseudostenhelia Wells, 1967 and Beatricella Scott, 1905, two typically shallow brackish water and marine genera. Some comments on their relationships are given.

Comparative phylogenomic patterns in the Baja California avifauna, their conservation implications, and the stages in lineage divergence

Comparative phylogeography explores the historical congruence of individual species phylogeographic histories to understand the factors that led to their current genetic and phenotypic structures. Various factors can result in currently co-distributed species exhibiting different phylogeographic patterns. The Baja California peninsula and adjacent desert regions provide several potential biogeographic barriers, which have left phylogeographic patterns in some but not all species. We discuss data from bird species found in this region that are relevant to understanding potential biogeographic barriers provided by the Vizcaino Desert. One goal is to compare different sources of molecular data. We show that previous work using mitochondrial markers and single-locus nuclear markers are concordant with similar analyses conducted with genome-wide SNP data (genotype-by-sequencing (GBS) for four bird species found along the Baja California peninsula and adjacent mainland, cactus wren, Gila woodpecker, California gnatcatcher, and LeContes thrasher. The cactus wren and LeContes thrasher show a concordant historical division at or near the Vizcaino Desert in north-central Baja California, the Gila woodpecker appears to be at an intermediate stage of divergence, whereas the California gnatcatcher lacks comparable phylogeographic structure. None of the species we analyzed are classified taxonomically in a way that captures their evolutionary history, with the exception of the LeContes thrasher. The evolutionary division at the Vizcaino desert is well known in other vertebrate species, and our study further corroborates the extent and importance of this biogeographic boundary. The areas north and south of the Vizcaino Desert, which contains considerable diversity, should be recognized as historically significant areas for conservation.

Anti-infective properties of medicinal plants from the Baja California peninsula, Mexico for the treatment of Fusarium oxysporum f. sp. basilici in organic sweet basil (Ocimum basilicum)

Certified-organic farming systems in Baja California Peninsula and Northwest Mexico are nationally and globally recognized, especially due to the production of vegetables and aromatic herbs under protected agriculture systems. Based on the background of some species of the flora of Baja California Sur (BCS) to inhibit a diversity of microorganisms, the effect of 22 medicinal plants of the region was explored to know the in vitro activity against the fungus Fusarium oxysporum f. sp. basilici isolated from basil (Ocimum basilicum L.). The plants processed as crude ethanolic and aqueous extracts were analyzed in duplicate (three replicates) evaluating the inhibition of mycelial growth and spore germination. In mycelial inhibition test, all plants extracts (1000 mg L-1) showed an effectiveness of 11 to 40% to inhibit F. oxysporum. The most effective plant extracts according to 50% effective inhibition dose (ED50), were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with an ED50 of 220, 303 and 3000 mg L-1, respectively. Tukey’s PostHoc tests indicated that H. monogyra and L. tridentata are ten times (ED50 <300 mg L-1) more effective than L. palmeri (ED50 3000 mg L-1). In addition, the dose-response trend analyzes according to the logarithmic-logistic model (drc packages), showed the maximum slope values ​​between 100 and 1000 mg L-1. In the spore germination inhibition tests, most ethanolic extracts (5000 mg L-1) showed an effectiveness between 21 and 80%. The results of this study demonstrated that the inhibitory potential of these plants used in BCS traditional medicine are a viable alternative for the control of F. oxysporum f. sp. basilici in organic basil production systems. Highlights 22 medicinal native plants from the Baja California peninsula can effectively inhibit (in vitro) oxysporum f. sp. basilica. The most effective species were Larrea tridentata, Hymenoclea monogyra and Lippia palmeri with a mycelial growth inhibition (ED50) of 220, 300 and 3000 mg L-1, respectively. In vitro effectiveness of Fusarium-growth inhibition of medicinal plants of BCS were in ED50 ranges from 220 to 3000 mg L-1. Creosote bush (L. tridentata) extract at a dose of 5000 mg L-1 can inhibit the fungal sporulation by up 80%. The ethanol-aqueous extract of the medicinal plants of BCS have the potential to be used for long-term control of the fusariosis disease in basil.

Two new species of nopal (Opuntia, Cactaceae) from the Baja California Peninsula (Mexico)

Two new species of prickly-pear/nopal (Opuntia sierralagunensis and O. caboensis, Cactaceae) are described and illustrated here; both occur in the tropical deciduous forest plant community found in the Cape region of the Baja California Peninsula, Mexico. Previously, these two species had been overlooked and were considered extreme forms of species described from the Sierra de La Giganta (e.g., O. comonduensis, O tapona), located hundreds of kilometers away. However, with an improved collection of specimens and field knowledge of the Opuntia species in the region, we have determined that these prickly-pears are new to science and are restricted to the Cape region. We provide justification to separate them from sympatric congeners and other similar species in the southern peninsula.

Morphological and genetic variation of black-tailed jackrabbit (Lepus californicus) populations separated by rivers

Two rivers in the hot desert of northwestern México have been considered as filter barriers in the distribution of mammals: Río Conchos in Chihuahua and Río Nazas in Durango. Between both rivers, the black-tailed jackrabbit, Lepus californicus, shows significant differences in external morphological traits. We investigated if these differences are supported by phylogenetical signals and compared them with populations living at similar latitudes in the Baja California Peninsula to determine the importance of the genetic variation caused by the rivers. An external mophology, and a cranial geometric morphometric analysis were performed using the dorsal, ventral, and lateral views of the skull; and a genetic analysis of cytochrome b gene. Measurements and fur color patterns of specimens from two continental groups, north of Río Conchos (NRC) and south of Río Nazas (SRN), were compared to four groups (A-D) inhabiting different latitudes of the Baja California Peninsula (BCP). The parietal region, zygomatic arch, and auditory bullae were identified as the main cranial structures related to skull shape; however, no differences were observed in size and shape between groups. The phylogenetic reconstruction of L. californicus showed that it is a monophyletic species, with high branch support values (100). It is represented by two polyphyletic subclades, one with haplotypes of the SRN and NRC populations and the other with haplotypes of the BCP populations. The average genetic distance (p-distance) and genetic differentiation (FST) between SRN and NRC were low (0.8 % and 0.09, respectively), with higher mean values between the BCP groups (1.23 % and 0.30, respectively). The statistical parsimony network of Cyt b did not identify a clear geographic genetic structure between haplotypes of SRN and NRC and they did not share haplotypes with the BCP populations. There are neither cranial geometric morphometric nor genetic differences between L. californicus populations related to either the rios Conchos or Nazas; thus, these rivers cannot be considered geographic barriers. However, there are morphological differences between the populations in Chihuahua and Durango and the populations inhabiting Baja California Peninsula, which may be associated with evolutionary distance and local habitat characteristics.