A new species of Profundulus (Cyprinodontiformes: Profundulidae) from the Honduran central highlands

A new species of Profundulus, Profundulus portillorum, from the Honduran central highlands is described. Profundulus portillorum belongs to the Profundulus labialis species group and is distinct from the Profundulus punctatus species group in that it lacks a humeral spot and less than half of the caudal fin is scaled. Within the P. labialis species group, P. portillorum has a more slender body, smaller eye, fewer anal rays, caudal rays and lateral‐line scales than other species. Forty‐one specimens were collected around emergent vegetation in the margins of two small (2–5 m in width, 20–40 cm in depth), high‐elevation (1300 m) tributaries of the Río Calam within the Río Ulúa drainage. These specimens represent the easternmost collection of any Profundulus and the first collection of any member of the P. labialis species group from Honduras.     

Occurrences of Prorocentrum minimum (Pavillard) in México

Prorocentrum minimum is a planktonic dinoflagellate known to produce red tides that can be harmful. To recognize localities and understand occurrences of Prorocentrum minimum blooms in Mexico, published data of plankton from 1942 to present, as well as unpublished data from the authors, were reviewed. Studies and reports covered marine and coastal waters of México during different periods. Presence of P. minimum were reported in the Pacific coast, Gulf of California, Gulf of México, and the Caribbean, but blooms have been only reported since 1990. Thirteen bloom events were recorded. Six occurred in shrimp ponds and seven near aquaculture regions or coastal areas where intensive agriculture is practiced. Most of the blooms can be associated with damage to the surrounding marine biota either in aquaculture ponds or open waters. Direct toxicity has not been fully evaluated, but data suggest that low oxygen may not easily explain all of the damage. Interestingly, for yet unknown reasons, cells belonging to the triangular morphotype have seldom been reported in México.     

Male reproductive cycle in Aspidoscelis costata costata (Squamata: Teiidae) from Tonatico,Estado de México,México

The purpose of this study was to investigate the reproductive cycle of a high‐elevation population of Aspidoscelis costata costata (1500–1600 m) and compare its reproductive cycle with that of other populations, species, and closely related genera. Adult male A. costata costata lizards were collected, and the reproductive tracts were removed and subjected to histological analyses. Testicular activity commences in March with maximum testicular activity and highest sperm abundance (in the epididymides) occurring between May and July. The testis remains at peak activity until September when a late regression/early quiescent phase is observed. Leydig cells follow this same pattern except these hormone‐producing cells remain at maximum secretory level through September. Sperm are present in the epididymides in April–September. This pattern is consistent with the spring recrudescence found in a multitude of male lizard taxa. However, this differs from the continuous cycle observed in some tropical Teiid species and other lizard taxa at high elevation. This study indicates that our knowledge about lizard spermatogenic cycles remains incomplete, and additional studies are required to fully understand the interactions between phenotype, evolution, phylogenetics and environment.     

Positive effects of native shrubs on three specially protected cacti species in Durango,México

The spatial association between the specially protected cacti Coryphanta durangensis, Echinocereus longisetus and Peniocereus greggii and potential nurse plants was evaluated, as was their relative position to the sun under the crown of the latter in the southern Chihuahuan Desert. The soil temperature under potential nurse plants was lower than under direct sunlight. There was more nitrogen and organic matter in the soil under Prosopis laevigata trees than in soil under direct sunlight. There were 68 plants of C. durangensis, 59 plants of E. longisetus and 157 of P. greggii. Only one individual of C. durangensis and one of E. longisetus grew outside the shade of the crown of other plants. Echinocereus longisetus was not associated with any particular species, but grew more often than expected by chance in the northern segment of the crown (i.e. the area most shaded in the afternoon). Coryphanta durangensis and P. greggii grew more often under P. laevigata than expected by chance. The effect of other plants, and P. laevigata in particular, on the facilitation of growth of protected cacti species should be considered in management plans of the Chihuahuan Desert, where mesquite (P. laevigata) is often harvested for charcoal production.     

Responses to Light in Epigean and Hypogean Populations of Gambusia Affinis (Cyprinodontiformes: Poeciliidae)

The responses to light among the fish Gambusia affinis, permanent residents of hypogean brackish water basins of the Spunnulate dolinas system of Torre Castiglione, in southeastern Italy, were studied at light intensities of 180 and 430 lux. These fish showed, on the average, a negative phototactic behaviour (scotophilia) with a low coefficient of variability. On the other hand, epigean, spring-dwelling individuals of G. affinis from the same region showed a positive phototactic behaviour with a greater variability in the responses when compared with cave-dwelling conspecifics. Possible causes for the detachment of hypogean from epigean forms are discussed.     

Aedes (Stegomyia) aegypti and Aedes (Howardina) cozumelensis in Yucatán State,México,with a summary of published collection records for Ae. cozumelensis

We collected mosquito immatures from artificial containers during 2010–2011 from 26 communities, ranging in size from small rural communities to large urban centers, located in different parts of Yucatán State in southeastern México. The arbovirus vector Aedes (Stegomyia) aegypti was collected from all 26 examined communities, and nine of the communities also yielded another container‐inhabiting Aedes mosquito: Aedes (Howardina) cozumelensis. The communities from which Ae. cozumelensis were collected were all small rural communities (<6,000 inhabitants) in the north‐central part of Yucatán State. These new collection records for Ae. cozumelensis demonstrate that this mosquito has a far broader geographic range in the Yucatán Peninsula than previously known. Ae. cozumelensis immatures were collected from both residential premises and cemeteries, with specimens recovered from rock holes as well as various artificial containers including metal cans, flower vases, buckets, tires, and a water storage tank. The co‐occurrence with Ae. aegypti in small rural communities poses intriguing questions regarding linkages between these mosquitoes, including the potential for direct competition for larval development sites. Additional studies are needed to determine how commonly Ae. cozumelensis feeds on human blood and whether it is naturally infected with arboviruses or other pathogens of medical or veterinary importance. We also summarize the published records for Ae. cozumelensis, which are restricted to collections from México's Yucatán Peninsula and Belize, and uniformly represent geographic locations where Ae. aegypti can be expected to occur.     

Contribution of native bees and Africanized honey bees (Hymenoptera:Apoidea) to Solanaceae crop pollination in tropical México

In the tropics the contribution of bees as pollinators of important economic indigenous crops remains largely undocumented. We studied the diversity of bee species visiting indigenous tomato (Solanum lycopersicon) and habanero pepper (Capsicum chinense) in subtropical Yucatán, México. The contribution of two native bees, Exomalopsis (E) and Augochloropsis (AG) was compared with that of the introduced Africanized Apis mellífera (HB) for pollinating unvisited flowers in both crops. Apis mellífera and stingless bees were dominant in habanero pepper but solitary bee species were important visitors of tomato. In spite of both crops being autogamic, there was a significant contribution of native bees for pollination of both tomato and habanero pepper. The comparison of fruit weight, number of seeds, and a pollination index based on the latter showed that E and AG were more effective pollinators compared to HB in both crops (ca. Spear’s index of ca. 0.7 vs. 0.35 respectively). In tomato, a further evaluation of the contribution to pollination provided by the three bee species was made using the rate of visits to flowers. Although E and AG were the most efficient pollinators at single flower visits in tomato, none of the three species (including HB) were able to provide single visits to all flowers per unit time to the crop. Our results underline the importance of maintaining diverse assemblages and abundant populations of bee species that can synergically contribute to the productivity of tomato and hot pepper in the Neotropics.     

Characterisation of myxozoan fauna of western mosquitofish,Gambusia affinis (Baird and Gerard) (Cyprinodontiformes: Poeciliidae), inhabiting experimental catfish ponds in Mississippi,USA

Systematic Parasitology - Characterising myxozoan taxa parasitising fish hosts in catfish aquaculture ponds is crucial to understanding myxozoan community dynamics in these diverse and complex...     

Length‐weight relationships of four fish species from the continental shelf of Yucatán (SW Gulf of México)

This paper presents length‐weight relationships (LWR) for four fish species from the continental shelf of Yucatán, at the Sonda de Campeche (southwestern Gulf of México). Samples were taken using shrimp trawl nets (5.71 cm squared mesh size in the cod‐end) in the mid‐summer of 2016. All LWRs were significant with r² values ranged from .946 to .994 and the values of exponent b, estimated using simple linear least squares of log‐transformed weight and length data, ranged from 2.54 to 3.10 (p < .001).     

Hydrology of winter–spring “red tides” in Bahía de Mazatlán, Sinaloa, México

“Red tide” events are frequent and periodical in Bahía de Mazatlán, Sinaloa, México. Yet, the ones observed from 4 February to 4 June 2000, showed some distinctive features: First, the dinoflagellates Prorocentrum balticum (85%), P. mexicanum (5%), and Ceratium furca (5%), dominated the composition of the blooms; Second, the average cell abundance by date was 1.3×10⁶ cells l⁻¹, with a range of 3.5×10³ to 24,500 × 10³ cells l⁻¹, well above previous records; Third, the temperature registered at 10–20 m deep was unusually cold (19 °C), below the normal average of 21.5 °C observed over the last 10 years. Salinity was high (35.9 psu) and showed very little influence on the water density gradient. A mean thermal stratification index (TSI), of 3.4, with a maximum of 7 °C, was observed throughout the period, in spite of a weak upwelling activity and intermittent strong NW winds which were unable to break up water column stratification. Temperature fluctuations at the surface and at the bottom layers showed a 30-day periodicity, suggesting some association with the lunar cycle. To explain the characteristics of the “red tides” registered in Bahía de Mazatlán during the winter–spring period of year 2000, it is proposed that the temperature and density stratification, stabilized further by internal waves that compensated for the weak upwelling activity and provided the necessary nutrients to the surface layer, favored the persistence and intensity of the harmful algal bloom events then observed.     

First Report of Botrytis cinerea Pers. on Salicornia bigelovii Torr. in North‐West México

Grey mould has been detected on Salicornia bigelovii Torr plants in nursery and in the wild in north‐west Mexico. Sampling of the grey mould was performed in the state of Sonora, Mexico, of wild as well as cultivated S. bigelovii plants. The samples were isolated, and based on morphology, the species was identified as Botrytis cinerea Pers. Koch's postulates were fulfilled by pathogenicity tests carried out in plated petri dishes on branches from the 3‐month‐old potted S. bigelovii plants. To our knowledge, this is the first report of the isolation and identification of the fungal pathogen B. cinerea from S. bigelovii in the north‐west Mexico.     

Callionymus omanensis,a new species of dragonet from Oman,north‐western Indian Ocean (Teleostei: Callionymidae)

A new species of deep‐living dragonet Callionymus omanensis from Oman is described on the basis of a single male specimen collected in a trawl from 500 m depth off the coast of Oman. The new species is characterized within the subgenus Bathycallionymus by having a small branchial opening; head short (3·9 in proportion to standard length); eye large (2·4 in proportion to head length); preopercular spine with a long, upcurved main tip, with a small antrorse barb and a larger antrorse spine, and with a strong antrorse spine laterally at the preopercular‐spine base, ventral margin smooth; first dorsal fin slightly higher than second dorsal fin (male); second dorsal fin distally straight; 17 pectoral fin rays; distal end of caudal fin slightly pointed, with two median unbranched rays bearing short filaments; first dorsal fin with basal black spot reaching from first to fourth membranes, third membrane with an ocellated distal black blotch; second dorsal fin with vertical dark grey bars; distal three‐fourths of anal fin black; upper half of caudal fin with oblique dark grey bars; pelvic fin dark grey, second ray basally with a black blotch. The new species is compared with similar species. Revised keys to callionymid species of the western Indian Ocean and the Red Sea, as well as species of the subgenus Bathycallionymus, are presented.     

<Emphasis Type="Italic">Careproctus kidoi</Emphasis>, a new Arctic species of snailfish (Teleostei: Liparidae) from Baffin Bay

Careproctus kidoi sp. nov. is described from the Baffin Bay between Greenland and Canada, in the northern most part of the western North Atlantic. During a series of bottom trawl surveys conducted in 1988–2004, 22 specimens of an undescribed species of Careproctus were caught at depths between 952 and 1,487 m. It differs from Arctic and North Atlantic congeners in the combination of the characters: pectoral fin rays 21–26, dorsal fin rays 54–60, anal fin rays 50–54, vertebrae 61–64; sucking disc oval, 4.2–6.6% SL; teeth simple; pyloric coeca 3–12; head pore formula (2-6-7-1); color light to dark brown, stomach dusky to dark brown, peritoneum black. It is generally found in deeper waters than the sympatric C. reinhardti.     

Gonopodial system review and a new fish record of Poeciliopsis infans (Cyprinodontiformes: Poeciliidae) for Lake Patzcuaro,Michoacan, central Mexico

Since 1997, Poeciliopsis infans Woolman 1894 has been recognized as a new inhabitant of Lake Patzcuaro, Michoacan in Central Mexico. Between February 1997 and October 1998, nine fish samples were collected at Lake Patzcuaro. Morphometric and meristic counts were conducted on a random selection of 40 organisms of both sexes of Poeciliopsis infans. Males of these viviparous fish posses a modified anal fin called gonopodium. The characteristic hemal spine on the 18th caudal vertebra for this species is described herein and the bony components of the gonopodial structure and suspensoria that together comprise the gonopodial system, which is important for taxonomic studies at various levels of classification were reviewed. Poeciliopsis infans displays a high degree of sexual dimorphism in body shape and anal fin anatomy with the most conspicuous difference observed in anal fin height, which averages 40% of SI in males and 17% in females. Comparisons between male and female anal fins are described herein as well as the possible impacts of this species on Lake Patzcuaro fish fauna.     

Comparative phylogeography of livebearing fishes in the genera Poeciliopsis and Poecilia (Poeciliidae: Cyprinodontiformes) in central Mexico

Aim To test the hypothesis that the vicariant event responsible for north–south divergences in two clades of the fish genus Poeciliopsis Regan was also responsible for north–south divergences in the fish Poecilia butleri Jordan. Location Central Mexico. Methods Parsimony, distance, maximum likelihood and Bayesian phylogenetic analyses of a mitochondrial gene. Molecular clock test and Bayesian analyses of divergence time. Results We report concordant phylogeographical patterns between two clades in the genus Poeciliopsis (i.e. the other formed by P. latidens Garman and P. fasciata Meek, and the other formed by P. presidionis Jordan and P. turneri Miller) and the clade of Poecilia butleri, with northern and southern individuals within each clade grouping into separate lineages. There is also evidence for slower substitution rates in Poecilia compared with Poeciliopsis. After taking into account these substitution rate discrepancies with Bayesian relaxed molecular clock analyses, north–south divergences in Poecilia butleri were equivalent to those reported for Poeciliopsis latidens‐fasciata and P. presidionis‐turneri. Main conclusions The same Plio‐Pleistocene vicariant event associated with geological activity of the Trans‐Mexican Volcanic Belt (TMVB) appears to have caused divergence in three different freshwater fish lineages. This study is an example of how comparative phylogeography can strengthen inferences about vicariant events in regions of high biological diversity and complex geological history such as the TMVB.     

Abundance and nightly activity behavior of a sylvan population of Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae) from the Yucatan,México

Triatoma dimidiata is the vector of Trypanosoma cruzi in the Yucatan Peninsula (YP). Earlier studies have shown that domestic and peri‐domestic populations of the vector originated from the sylvan stock and that effectiveness of insecticide‐spraying was affected by re‐infestations of houses from the sylvan T. dimidiata population. In addition, in the YP most previously published reports have focused on domestic and peri‐domestic populations and very little is known about the nocturnal behavior of the sylvan populations. The main aim of our study was to determine the nightly activity patterns of adult T. dimidiata in a selected location in the YP. Secondly, we sought to document the reproductive status and infection rate of active females. During eight sampling nights spaced from late March to late July, 2007, we collected 544 adult T. dimidiata. We found that square‐cloth illuminated white traps were effective to attract the sylvan individuals and that T. dimidiata adults exhibited a unimodal activity pattern throughout the night. The accumulated mean of captured bugs also showed a non‐linear distribution for females and males. Furthermore, we found that male and female catches were significantly correlated with the means of temperature and humidity recorded during the sampling period. Out of 46 dissected females, we observed that 43.5% of females had fully‐formed eggs in their abdomens, and only two females (4.4%) had sperm within the spermatheca. The infection rate of T. dimidiata harboring T. cruzi was found to be 3.7%. The implications of the light attraction to bugs and potential dispersal capabilities are discussed in the paper in the context of infestation/re‐infestation of rural houses by sylvan T. dimidiata flying adults.     

A re‐examination of the molecular phylogeny and biogeography of the genus Schizothorax (Teleostei: Cyprinidae) through enhanced sampling,with emphasis on the species in the Yunnan–Guizhou Plateau,China

The mitochondrial DNA cytochrome b sequences of 36 Schizothorax species from 51 localities in the Yunnan–Guizhou Plateau (YGP) and its adjacent areas were analysed. Maximum parsimony, Maximum likelihood and Bayesian phylogenetic analyses were performed to examine the relationships of Schizothorax species. A hypothesis of the phylogenetic relationships of the species is given. A relaxed molecular clock based on Bayesian evolutionary analysis was used to tentatively calculate the divergence times of Schizothorax. Samples from the YGP were tentatively grouped into three geographically distributed clades: the Tsangpo‐Irrawaddy, the Mekong‐Salween and the Trans‐Jinsha River (including Jinsha, Red, Nanpan and Beipan Rivers). Calibration of the molecular clock revealed that two geological periods, the late Miocene about 10 million years before present (Myr BP) and the Pliocene (4.0 Myr BP), were important times in the vicariant speciation of Schizothorax. The phylogenetic history of the species is congruent with events caused by the uplift of the Tibetan Plateau and the YGP. The divergence of Schizothorax species in YGP began in the Pliocene. Our phylogenetic trees did not support the hypothesis that the paleo Jinsha River was drained through the Yangtze River‐Jianchuan Lake‐Erhai Lake to the Red River. Schizothorax in the Beipan River were derived from the Jinsha River.