A new Hesperodiaptomus Light (Copepoda, Calanoida, Diaptomidae) from Mexico with comments on the distribution of the genus

A new species of the freshwater planktonic copepod genus Hesperodiaptomusis described from material collected in several water bodiesin the state of Morelos, central Mexico. Hesperodiaptomus morelensisn. sp. differs from its congeners in having a very reduced endopodon the male fifth right leg, and a hook-shaped cuticular processon the inner margin of the first exopodal segment of the sameleg. Besides other characters of the female fifth legs, thenew species has a distinctive genital somite, with asymmetricallateral wing-like processes. This species seems to be closelyrelated to H. kiseri mainly because of similarities betweenthe male fifth legs and the structure of the female genitalsomite. This predominantly nearctic genus is known to be distributedmainly in north-western and central North America, althougha few species have been recorded in north-eastern Asia (Siberia).Hesperodiaptomus has not been recorded previously south of California.Apparently, this genus radiated in North America and spreadin different directions. The apparent disjunct distributionof at least two species (including the new one) could be explainedas resulting from a previous extensive radiation related toglaciation and consequent post-glacial repopulation that mighthave left these forms as stranded remnants, or by dispersalprocesses: central Mexico is connected with North America bytwo high-altitude potential passages. The new species seemsto be restricted to a high altitude area in Mexico. It seemsunlikely that species of Hesperodiaptomus will be recorded furthersouth on the American continent.     

Redescription and distribution of Mastigodiaptomus montezumae (Copepoda, Calanoida, Diaptomidae) in Mexico

Mastigodiaptomus montezumae is redescribed on the basis of material from several localities in Mexico. It is characterized by an asymmetrical fifth pediger in both sexes. It appears to be restricted to central Mexico, where it is quite common. It is associated with M. albuquerquensis and occasionally with L. siciloides and Leptodiaptomus novamexicanus.     

A new genus of Cletopsyllidae (Copepoda,Harpacticoida) from Gulf of Mexico

A new genus and new species of the family Cletopsyllidae Huys & Willems, 1989 from deep-sea sediment in the Gulf of Mexico, are reported and fully described and illustrated. The new genus Pentacletopsyllus (type species: P. montagnisp. n.) can be distinguished from the four known genera of the family by antennule segmentation, length ratio of first and second endopodal segments of P1, and armature pattern on P5 exopod. It also differs from its sister genera by the rostrum being bifid at the tip, third segment of the female antennule having a smooth posterior margin, the baseoendopod of P5 with biarticulate outer setophore bearing basal seta, and female caudal rami without lobate expansion. A revised key to species of the family Cletopsyllidae Huys & Willems, 1989 is provided.     

A new Stygonitocrella Petkovski (Copepoda: Harpacticoida) from a cave in Northern Mexico with comments on the taxonomy of the genus

The cave-dwelling harpacticoid copepod fauna of Mexico is still yet to be known. There are only a few records related to karstic caves, but most refer to epigean forms. The analysis of samples collected in a cave system in Northern Mexico yielded two female specimens of an unknown harpacticoid copepod species which is described herein. It was assigned to the genus Stygonitocrella Petkovski, 1976 mainly because of the presence of a single endopodal segment on legs 1–4; the new species, S. mexicana n. sp. differs from its congeners by a combination of characters related to the segmentation and armature of the swimming legs 1–4, the fifth leg of the female, and the strcture of the antennae. Based on the current limits of Stygonitocrella, two new subgenera are proposed to recognize different morphological patterns based on the presence or absence of an inner baseoendopodal lobe in the female fifth leg, a character not evaluated before. This lobe is absent in the new species and in other five species now contained in the subgenus Eustygonitocrella. A lobe is present in the new subgenus Fiersiella, also with six species. This is the second record of Stygonitocrella in North America, after S. (Fiersiella) sequoyahi Reid, Hunt & Stanley, 2003; it is the only North American cave-dwelling species of the genus. It is suggested that the influence of marine transgressions in Northern Mexico was related to the origin of the new species as part of a group of troglobitic forms originated from marine interstitial ancestors that colonized the freshwater caves. A key for the identification of all the known species of Stygonitocrellais also provided.     

A new species of Notodiaptomus Kiefer, 1936 (Copepoda,Diaptomidae) from the Amazon and Orinoco River Basins

A new species of Notodiaptomus, Notodiaptomus simillimus sp. nov., based on the female originally but erroneously assigned to Rhacodiaptomus calatus, and the corresponding newly discovered male, is described and illustrated in detail. The designation of the female as a new species of Notodiaptomus, and the recognition of the corresponding new male, is based on detailed morphological and biometrical studies, analysis of the known distribution and material from laboratory cultures. Morphological analysis demonstrated that the female shares the form of the external genital area and setal armature of the exopod 2 of leg 5 with other species of Notodiaptomus but they differ from those exhibited by species of Rhacodiaptomus. The distributions of the female and male assigned to Notodiaptomus simillimus sp. nov. overlap and include the Atabapo and Guaviare Rivers and Lago Calado. On the other hand, the distributions of the males and females originally assigned to R. calatus are disjunct and where they overlap, that is, in Lago Calado, each is accompanied by its respective mate. Laboratory cultures showed that, as expected, copulation did not occur between males and females described originally as R. calatus. This experiment demonstrated the existence of reproductive isolating mechanisms between these females and males, and confirmed the existence of two distinct genetic pools, i.e. two different species, the original males being of the valid R. calatus and the female a new Notodiaptomus. This female and the corresponding newly discovered male are N. simillimus. The new species is closely related to N. coniferoides.     

The genus Mixodiaptomus Kiefer, 1932 (Copepoda,Diaptomidae) in Spain

The distribution of the Calanoid genus Mixodiaptomus was studied in a large number of pools and small lakes scattered over Spain. Four species occur: M. incrassatus, M. kupelwieseri, M. ortizi and M. laciniatus, the latter in 2 subspecies (M. laciniatus laciniatus and M. laciniatus atlantis). M. ortizi is described as a new species. M. laciniatus lives in mountains, while all other species occur in the plains. M. incrassatus is found all over the country, M. kupelwieseri only in the eastern part of Catalonia, M. laciniatus atlantis in Andalucia and M. ortizi in the central lands called Mesetas. All live in little mineralized waters and only M. incrassatus and M. laciniatus atlantis occur in clayey waters.     

A new genus and species of cyclopoid (Crustacea,Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico

A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13.     

A new diatom (Bacillariophyceae) genus with two new species from New Mexico,USA

A new diatom (Bacillariophyceae) genus and two new species are described from the arid region of the North American southwest. The new genus, Playaensis, and new species, P. circumfimbria and P. furtiva, are distinguished by frustule morphology and autecology. Playaensis possesses unique, narrowly lunate longitudinal ribs bordering the raphe and spathulate spines, but their evolutionary relationship to known genera is unclear. In Payton Lake, New Mexico, P. circumfimbria and P. furtiva are rare in the diatom community, and their geographic and geological extent are not known, but they may be restricted to alkaline, slightly saline lakes of the region.     

Keraladiaptomus rangareddyi a new genus and new species of Diaptominae (Copepoda,Calanoida, Diaptomidae) from a temporary pond in Mattam,Kerala State,India

Calanoid copepods, belonging to the new genus and species Keraladiaptomus rangareddyi, were collected from temporary ponds in Kerala State, India. The new genus belongs to the family Diaptomidae, subfamily Diaptominae. It is described in detail and its affinity to the related genera, Arctodiaptomus Kiefer, 1932 and Eodiaptomus Kiefer, 1932, discussed.     

A new species of Ceratozamia (Zamiaceae) from the Sierra Madre of Chiapas, Mexico, with comments on species relationships

The new species Ceratozamia vovidesii from a Pleistocene floristic refuge in southern Mexico is described and illustrated. It show an affinity with C. matudae Lundell and C. mirandae Vovides, Pérez-Farrera & Iglesias from Chiapas, but it differs from them in leaf, male and female cones, and trunk morphology.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 393–400.     

A new genus and species of Metopiinae (Hymenoptera, Ichneumonidae) from Mexico

A new genus of Metopiinae, Ojuelos Khalaim, gen. n., with a single species, Ojuelos juachicus Khalaim & Ruíz-Cancino, sp. n., is described from Jalisco Province in central Mexico. Ojuelos belongs to the group of three genera (Cubus Townes & Townes, Colpotrochia Holmgren and Triclistus Förster) having a high lamella separating the antennal sockets and reaching the median ocellus (this lamella possesses a dorsal groove in it, just below the median ocellus), but differs from these genera primarily by 1) face and clypeus not convex in lateral view, 2) face separated from clypeus by a shallow transverse impression, 3) mandible with lower tooth very strongly reduced, 4) flagellomeres of antenna strongly transverse, and 5) dorsal carinae of propodeum reduced. A portion of the key to the genera of Metopiinae is provided to distinguish the new genus.     

A new species of Ceratozamia (Zamiaceae) from Oaxaca, Mexico with comments on habitat and relationships

Ceratozamia chimalapensis sp. nov. is described and illustrated. It is related to C. mirandae Vovides, Pérez-Farrera & Iglesias from Chiapas, but differs in trunk and peduncle size as well as in diameter of both megastrobili and microstrobili. Petiole, megasporophyll and indument colour also differ from that of C. mirandae . Ceratozamia chimalapensis forms part of the C. norstogii D.W.Stev. species complex, a group of ceratozamias with narrow leaflets growing in the herbaceous layer of oak forests in southern Mexico. These forests were severely affected by forest fires during 1998 and we recommend an IUCN Red List Category of CR B.1. Speciation in Ceratozamia has been discussed in the light of floristic refugia.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 169–175.     

A new species of Thenardia (Apocynaceae,Apocynoideae) from Chiapas,Mexico, with notes on the genus

A new species,Thenardia chiapensis, is described and illustrated. The new species is the first taxon in the genus to have its fruits, two fused follicles, described and illustrated. In addition, observations ofT. floribunda specimens have revealed the existence of a novel character, coiled filaments, previously undescribed for the genus.     

A new species in the genus Dioon (Zamiaceae) from north-central Oaxaca, Mexico

Dioon argenteum sp. nov. (Zamiaceae) is described from northern Oaxaca, México. Flat leaves, and persistently tomentose, slightly imbricate leaflets with marginal prickles characterize this species. The specific epithet argenteum was chosen to describe the silver appearance of the persistent tomentum covering the new leaves. D. argenteum appears to have affinities with D. purpusii and D. califanoi.   © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 471–476.     

A new genus and two new species of Canthocamptidae (Copepoda,Harpacticoida) from caves in northern Italy

Lessinocamptus n. gen. is established toaccomodate three species from northern Italian caves.It can be ascribed to the family Canthocamptidae Sars1906 and is distinguished from the other genera by thecombined characters of: antenna exopod 1-segmented andbearing 3 setae (or 1 seta and 1 spine); mandibularpalp 2-segmented with distal article bearing 5 setae;swimming legs exopods 3-segmented; setal formula ofexopods: P1 0.0.022; P2 0.1.112; P3 0.1.212; P4 0.1.212; P1endopod 2-segmented; P2 endopod 1- or2-segmented; female P3 endopod 1- or 2-segmented, maleP3 endopod 3-segmented and modified as usual inCanthocamptinae; male P5 baseoendopod with 2 spinesand exopod with 3 spiniform setae. Three species aredescribed in detail: L. caoduroi n.sp. from thevadose zone of Lessinian caves, L. insoletus(Chappuis 1928) and L. pivai n.sp. from caveBuso della Rana near Vicenza.     

Yansacyclops ferrarii,new genus,new species (Copepoda: Cyclopoida) from the Amazon Basin,Brazil

Yansacyclops ferrarii, new genus, new species (Copepoda: Cyclopoida) is described from the plankton of Rios Guamá and Acará Grande near Belém, State of Pará, Brazil.     

A new species of Dicranocentrus (Collembola,Entomobryidae) from China with comments on the systematic position of the genus

Dicranocentrus liuae sp. n. is described from the northern subtropical region of China. The new species is most similar to D. wangi Ma & Chen, 2007, but differs from it in the relatively shorter Ant. V, the 1+1 central macrochaetae on Abd. III, the number of chaetae on tenaculum, and the absence of dental spines. The systematic position of Dicranocentrus is also discussed. Present evidence, particularly S-chaetotaxy, indicates that the genus is closer to Heteromurus than to the unscaled species of Orchesella and Orchesellides.     

A new species of Peltidium Philippi, 1839 (Crustacea,Copepoda, Harpacticoida) from the Pacific coast of Mexico

During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.