Seasonal and interannual variation of ichthyoplankton off the coast of the Moroccan Sahara

Changes in the qualitative and quantitative composition of ichthyoplankton off the coast of the Moroccan Sahara (21–28° N) in different seasons of 1994–2007 are analyzed. In this region, the pelagic eggs and larvae of over 100 fish species belonging to 62 families have been recorded. In cold periods, off the coast of the Moroccan Sahara there is peak in the spawning of fish of the subtropical fauna. The majority of them are European pilchard Sardina pilchardus, common scad Trachurus trachurus, and Atlantic mackerel Scomber japonicus. In warm periods there is intensive spawning of fish of the tropical fauna. Among them, dominants are round sardinella Sardinella aurita, West-African scad Trachurus trecae, and Atlantic bonito Sarda sarda. The spawning biomass of principal commercial fish is calculated by the quantity of eggs laid by females. The environmental factors are indicated that influence the fluctuation of abundance and distribution of ichthyoplankton in the region under consideration.     

Age-based demography and reproductive biology of three <Emphasis Type="Italic">Epinephelus</Emphasis> groupers, <Emphasis Type="Italic">E. polyphekadion,E. tauvina,</Emphasis> and <Emphasis Type="Italic">E. howlandi</Emphasis> (Serranidae), inhabiting coral reefs in Okinawa

The demography and reproductive biology of three Epinephelus groupers (Serranidae), namely E. polyphekadion, E. tauvina, and E. howlandi in the Yaeyama Islands, Okinawa, were examined based on age assessment using otoliths and gonadal histology. The maximum ages for these three species were 26 year, 23 year, and 17 year. The von Bertalanffy growth functions were also determined for each species. The size and age at 50% female maturity were estimated to be 358 mm in total length (TL) and 6.0 year for E. polyphekadion, 371 mm TL and 6.7 year for E. tauvina, and 327 mm TL and 4.1 year for E. howlandi, respectively. Significant differences between the sexes in size and age frequencies were found in all three species, with males being larger and older than females, or transitional individuals. These results strongly indicated that the population of these three grouper species showed monandric protogynous hermaphroditism. The sex ratios of E. polyphekadion and E. tauvina were biased in favor of females, but that of E. howlandi was equivalent between sexes. The relative sizes of ripe testes indicated that the intensity of sperm competition varied among species suggesting different mating system of each species. Reproductive seasonality was similar among species, with active vitellogenesis coinciding with the annual rise in water temperature. The active spawning period was determined to be between April and May for E polyphekadion, in May for E. howlandi, and from March to June for E. tauvina.     

Reproduction and development in some species of the weakly electric genus <Emphasis Type="Italic">Campylomormyrus</Emphasis> (Mormyridae,Teleostei)

Reproduction in captivity of four species of the mormyrid genus Campylomormyrus was investigated. Cyclical reproduction was provoked by changing water conductivity (C) alone: decreasing C led to gonadal recrudescence, an increase induced gonad regression. Data on the reproduction and development of three species are presented. All three species are indeterminate fractional spawners. Spawning intervals ranged from 6 to 66 days in C. rhynchophorus, 10–75 days in C. tshokwe, and 18 days in C. compressirostris (calculated values). Fecundities (eggs per fractional spawning) ranged from 70 to 1570 eggs in C. rhynchophorus, 100–1192 in C. tshokwe, and 38–246 in C. compressirostris. Spawnings/ovipositions occurred during the second half of the night; no parental care was observed; no special spawning substrates were necessary. C. compressirostris successfully spawned in breeding groups, C. rhynchophorus as pair. Agonistic behavior in the C. tshokwe pair forced us to divide the breeding tank; therefore, only ovipositions occurred. However, injection of an artificial GnRH hormone allowed us to obtain ripe eggs and sperm and to perform successful artificial reproduction. All three species produce yolky, slightly sticky eggs. Egg diameter ranges from 2.3–3.0 mm. Hatching occurred on day 3, feeding started on day 11. Transition from larval to juvenile stage occurred at around 20 mm total length (TL). At this size C. rhynchophorus developed a higher body than the two other species and differences between the species in the melanin pigmentation of the unpaired fins occurred. Between 32 and 35 mm TL the upper and lower jaws started to elongate.     

Feeding of pelagic fish in waters of Mauritania: 2. Representatives of Families Carangidae,Scombridae, Pomatomidae,and Trichiuridae

Feeding peculiarities of mass pelagic ichtyophagous fish from the Canary upwelling waters and frontal zones of Mauritania have been investigated: vadigo Campogramma glaycos, false scad Caranx rhonchus, bluefish Pomatomus saltatrix, Atlantic bonito Sarda sarda, West African Spanish mackerel Scomberomorus tritor, large-eyed hairtail Trichiurus lepturus and pompano Trachinotus ovatus. These species feed on epipelagic fish living or forming temporary agglomerations at the depths up to 200–250 m from the surface.     

Blood Feeding Status,Gonotrophic Cycle and Survivorship of <Emphasis Type="Italic">Aedes (Stegomyia) aegypti</Emphasis> (L.) (Diptera: Culicidae) Caught in Churches from Merida,Yucatan, Mexico

Blood-feeding status, gonotrophic cycle, and survival rates of Aedes (Stegmyia) aegypti (L.) was investigated in catholic churches from Merida, Yucatan. Female Ae. aegypti were caught using backpack aspirator during 25 consecutive days in rainy (2015) and dry season (2016). Blood-feeding status was determined by external examination of the abdomen and classified as unfed, fed, and gravid. Daily changes in the parous–nulliparous ratio were recorded, and the gonotrophic cycle length was estimated by a time series analysis. Also, was observed the vitellogenesis to monitoring egg maturity. In total, 408 females Ae. aegypti were caught, and there was a significant difference in the number of females collected per season (Z = ?6.729, P ≤ 0.05). A great number was caught in the rainy season (n = 329). In the dry season, 79 females were caught, which the fed females were twice greatest than the unfed. The length of gonotrophic cycle was estimated on the base of a high correlation coefficient value appearing every 4 days in rainy at 26.7 ± 1.22°C, and 3 days in dry season at 29.8 ± 1.47°C. The daily survival rate of the Ae. aegypti population was higher in both seasons, 0.94 and 0.93 for the rainy and dry season, respectively. The minimum time estimated for developing mature eggs after blood feeding was similar in both seasons (3.5 days in rainy versus 3.25 days in dry). The measurement of the vectorial capacity of Ae. aegypti in catholic churches could help to understand the dynamics of transmission of arboviruses in sites with high human aggregation.     

Reproductive features of <Emphasis Type="Italic">Upeneus margarethae</Emphasis> (Mullidae), a species recorded in the coastal zone of Vietnam for the first time

The species Upeneus margarethae described recently from the western Indian Ocean is recorded in the coastal zone of Vietnam for the first time. The reproductive features of the representatives of the species from southern Central Vietnam (Nha Trang Bay), Central Vietnam (Da Nang), and North Vietnam (Ha Long Bay) are studied. Based on the analysis of maturity stages of female’s ovaries and gonadosomatic index, the fishes spawn over the entire year in Central Vietnam, but the spawning interruption is observed in North Vietnam during a winter season. In Nha Trang Bay, 50% of females reach sexual maturity at the body length (FL) 9.8 cm. Based on histological structure of ovaries and frequency distribution of oocyte diameter before the spawning, the oogenesis is continuous. Anomalous oocyte structure is registered in 20% of the females. Egg morphology is described for 3 h after activation of ovulated oocytes. A comparison of reproductive parameters in U. margarethae and U. tragula is conducted.     

Age,growth and reproduction of the Iranian goby, <Emphasis Type="Italic">Ponticola iranicus</Emphasis> (Perciformes: Gobiidae) from the southern Caspian Sea basin

To estimate reproductive biology of Ponticola iranicus Vasil’eva et al., 2015, in Sefidroud River in the southern Caspian Sea basin age, sex ratio, fecundity, oocytes diameter, gonadosomatic, modified gonadosomatic and dobriyal indices were measured. Regression analyses were used to find relations between fecundity and fish size (length and weight), gonad weight, and age. Mature females and males were longer than 46 and 49 mm in total length, +1 in age. The Von Bertalanffy growth models were L _∞ = 23.00 cm (TL), K = 0.21, t ₀ =–0.25 for all specimens. Sex ratio was 1: 1.32 in favor of males. The average egg diameter was 0.96 mm. The spawning period extended from late February to late April. The averages of absolute and relative fecundity were calculated as 536.9 and 81.3, respectively. The absolute fecundity was significantly related to the body length and weight, as well as gonad weight.     

Regulation of population numbers in the <Emphasis Type="Italic">Rana arvalis</Emphasis> frog according to the results of long-term observations on the same population

An analysis of the results of long-term stationary studies (1987–1996) on a Rana arvalis population showed that the mean body length and reproductive parameters of females increased with age. Significant interannual changes in body length and egg size (but not in fecundity and reproductive effort) were also accounted for by conditions of the warm season preceding the breeding season. The dependence of egg diameter and reproductive effort on the female body length weakened with age, and only the relationship between body length and fecundity was characterized by positive allometry. The survival rate of mature females depended on the premetamorphic survival rate and, therefore, was higher in earlier generations, in which the aquatic phase proceeded under more favorable conditions. The rate of reproduction (R ₀) decreased and, therefore, further population growth slowed down only after the initial abundance of the generation had reached a relatively high level. An increase in the initial abundance of the generation exerts a strong influence on R ₀ via a decrease in the survival of premetamorphic animals and, to a lesser extent, via a decrease in the body length and fecundity of tree-and four-year-old females. Changes in the annual abundance of breeding females in R. arvalis were more abrupt and less prolonged than those in the sympatric R. temporaria population. The holding capacity of the environment for the aquatic phase of the R. arvalis life cycle was higher than that for R. temporaria. Therefore, the population abundance of R. arvalis, compared to R. temporaria, was not subject to stringent negative feedback regulation dependent on the initial number of animals.     

Reproductive biology and management of two commercially important groupers in the SW Atlantic

The reproductive biology of Epinephelus morio (red grouper) and Mycteroperca bonaci (black grouper) were evaluated based on 533 specimens collected from artisanal fisheries landings in the Abrolhos Bank, Brazil, between May 2005 and September 2012. Sex ratio for the black grouper was 1:14 (n = 155 females and 11 males; 26.1–147 cm TL) and 1:10 for the red grouper (n = 334 females and 33 males; 15.0–96.0 cm TL). For both species, highest values of the gonadosomatic index (GSI) for females were recorded between July and October, indicating spawning during the austral winter. The length at first maturity (L₅₀) for females was estimated at 62.0 and 47.0 cm TL for the black and red grouper, respectively. Batch fecundity based on TL and TW ranged from 2 to 15.4^?10⁶ and 1.5 to 13.7^?10⁶ for the black and red grouper, respectively. Interviews with experienced fishers revealed that spawning seasons of both groupers are largely unrecognized. Results demonstrate a positive relationship between GSI peaks, lower temperatures and stronger winds. The information provided herein may help decision-making regarding fisheries management and conservation for E. morio and M. bonaci at various levels of governance in the Abrolhos Bank, the region with the largest and richest coralline reefs in the South Atlantic.     

Does simultaneous and sympatric reproduction between two native spined loaches lead to reproductive interference and local extinction?

Reproductive interference occurs when fitness of females of one species decreases because of misdirected courtship behaviors by males of another species. Reproductive interference strongly excludes either species in the interaction but it does not persist for long on an evolutionary time scale. Therefore, reproductive interference between a pair of co-evolved native species is difficult to observe because exclusion ends the interaction even if even the potential for reproductive interference still exists. However, anthropogenic environmental changes can bring about secondary contact between two species and trigger reproductive interference, leading to local species extinction. We demonstrated this phenomenon with two native spined loaches: Cobitis magnostriata (Cmag) and C. minamorii oumiensis (Cmio). In 2015 and 2016, we investigated the spatiotemporal dynamics of adults and juveniles of both species to estimate the effects of the relative abundance of adults on reproductive success. Additionally, we surveyed the distribution of juveniles and investigated the proportion of gravid females which failed to reproduce at the end of the spawning season. In 2016, Cmio juveniles were fewer than in 2015, although the abundances of Cmio adults were similarly low in both years and the Cmag adults were more abundant in 2016 than in 2015. The juveniles of the two species exhibited similar spatiotemporal dynamics. At the end of the spawning season, Cmag males were abundant and most Cmio females failed to reproduce. These results suggest that the two species share spawning habitats and seasons and that Cmag males exert reproductive interference on Cmio females. This report is the first of a study suggesting that anthropogenic environmental changes triggered reproductive interference between native species in the field.     

Bacterial metabolites from intra- and inter-species influencing thermotolerance: the case of <Emphasis Type="Italic">Bacillus cereus</Emphasis> and <Emphasis Type="Italic">Geobacillus stearothermophilus</Emphasis>

Bacterial metabolites with communicative functions could provide protection against stress conditions to members of the same species. Yet, information remains limited about protection provided by metabolites in Bacillus cereus and inter-species. This study investigated the effect of extracellular compounds derived from heat shocked (HS) and non-HS cultures of B. cereus and Geobacillus stearothermophilus on the thermotolerance of non-HS vegetative and sporulating B. cereus. Cultures of B. cereus and G. stearothermophilus were subjected to HS (42 or 65 °C respectively for 30 min) or non-HS treatments. Cells and supernatants were separated, mixed in a combined array, and then exposed to 50 °C for 60 min and viable cells determined. For spores, D values (85 and 95 °C) were evaluated after 120 h. In most cases, supernatants from HS B. cereus cultures added to non-HS B. cereus cells caused their thermotolerance to increase (D ₅₀ 12.2–51.9) when compared to supernatants from non-HS cultures (D ₅₀ 7.4–21.7). While the addition of supernatants from HS and non-HS G. stearothermophilus cultures caused the thermotolerance of non-HS cells from B. cereus to decrease initially (D ₅₀ 3.7–7.1), a subsequent increase was detected in most cases (D ₅₀ 18–97.7). In most cases, supernatants from sporulating G. stearothermophilus added to sporulating cells of B. cereus caused the thermotolerance of B. cereus 4810 spores to decline, whereas that of B. cereus 14579 increased. This study clearly shows that metabolites in supernatants from either the same or different species (such as G. stearothermophilus) influence the thermotolerance of B. cereus.     

Biogeography and phenology of oviposition preference and larval performance of <Emphasis Type="Italic">Pieris virginiensis</Emphasis> butterflies on native and invasive host plants

In invaded environments, formerly reliable cues might no longer be associated with adaptive outcomes and organisms can become trapped by their evolved responses. The invasion of Alliaria petiolata (garlic mustard) into the native habitat of Pieris virginiensis (West Virginia White) is one such example. Female butterflies oviposit on the invasive plant because it is related to their preferred native host plant Cardamine diphylla (toothwort), but larvae are unable to complete development. We have studied the impact of the A. petiolata invasion on P. virginiensis butterflies in the Southeastern USA by comparing oviposition preference and larval survival on both plants in North Carolina (NC) populations without A. petiolata and West Virginia (WV) populations where A. petiolata is present. Larval survival to the 3rd instar was equally low in both populations when raised on A. petiolata. Mean oviposition preference on the two plants also did not differ between populations. However, we found a seasonal effect on preference between early and late season flights within WV populations. Late season females laid 99% of total eggs on A. petiolata while early season females utilized both host plants. Late season females were also less likely to lay eggs than early season females. This change in preference toward A. petiolata could be driven by the early senescence of C. diphylla and suggests a seasonal component to the impact of A. petiolata. Therefore, the already short flight season of P. virginiensis could become further constrained in invaded populations.     

Population Dynamic of the Mudskipper <Emphasis Type="Italic">Periophthalmus waltoni</Emphasis> Koumans, 1941 from the Bay of Hormozgan Province,Persian Gulf

We studied the population structure and reproductive biology of the mudskipper Periophthalmus waltoni Koumans, 1941, living on the mudflats of bay of Hormozgan province, Persian Gulf. The specimens were haphazardly and monthly collected from August 2008 to July 2009. A total of 2060 fishes was sampled, sexed 690 of which 221 (32%) were males, and 469 (68%) females. The total length (TL) and weight relationship demonstrated growth in both sexes was isometric with the function W = 0.0078TL^3.06. The asymptotic length (L∞) and growth coefficient (K) were estimated as 16.5 cm and 0.75 yr^–1, respectively. Age of the fish at zero length (to) was calculated–0.35 and the longevity was attained 3.65 year. The estimated Von Bertalanffy function was TL_(t) = 16.5[1–exp(–0.75(t + 0.35))]. Natural mortality (M) was estimated 1.74 yr^–1. Four cohorts were distinguished annuallywith mean of TL = 7.35, 10.17, 12.74 and 13.92 cm. The maximum recruitment rate was in January at 17.5%. The overall sex ratio (F: M) (1: 0.49) was significantly different than 1: 1. The peak of the gonadosomatic index (GSI) occurred in February. The size at onset of sexual maturity (LM₅₀)wasestimated at TL = 12 cm. The mean of absolute and relative fecundity were estimated as 3558 ± 2203 and 257 ± 101 eggs, respectively.     

<Emphasis Type="Italic">Melampsora pakistanica</Emphasis> sp. nov., a new rust fungus on <Emphasis Type="Italic">Euphorbia helioscopia</Emphasis> (Sun spurge) from Pakistan

A rust fungus was found on the leaves of Euphorbia helioscopia during a field study in Pakistan. Previously, Melampsora euphorbiae, M. euphorbiae-gerardianae and M. helioscopiae have been reported on E. helioscopia, the first two of which are also known from Pakistan. Morphological observations of the newly collected rust samples detected some differences from the previously described Melampsora species on E. helioscopia. The molecular analysis of the ITS and LSU sequences also detected that the rust is different from the previously reported rusts described from E. helioscopia. Based on both morphological comparisons and sequence analysis, the rust is described here as M. pakistanica sp. nov. This species could have potential as a bio-control agent against its host plant—E. helioscopia—which is a weed of wheat fields in Pakistan and elsewhere in the world.     

Morphological and molecular-genetic distinctions between adult mosquitoes <Emphasis Type="Italic">Culex torrentium</Emphasis> Martini and <Emphasis Type="Italic">C. pipiens</Emphasis> Linnaeus (Diptera,Culicidae) from Moscow Province

Morphological, biological, and molecular-genetic characteristics of Culex pipiens and C. torrentium, collected from two sites in Moscow and five sites in Moscow Province, were studied. Our results demonstrated the absence of any differences between females of these species in the R ₂/R ₂₊₃ ratio. Figures and photographs of the male genitalia are given. Differences between the species in the mDNA cytochrome oxydase I gene and the 1TS2 region of the rDNA were revealed. 90–100% of C. pipiens and 0% of C. torrentium were infested with the endosymbiotic bacterium Wolbachia pipientis.     

Discovery of a Highly Virulent Strain of <Emphasis Type="Italic">Photorhabdus luminescens</Emphasis> ssp<Emphasis Type="Italic">. akhurstii</Emphasis> from Meghalaya,India

Photorhabdus is an insect-pathogenic Gram negative enterobacterium found in the gut of Heterorhabditis nematodes. Photorhabdus is highly virulent to insects, and can kill insects rapidly upon injection at very low concentrations of one to few cells. We characterized the virulence of Photorhabdus symbionts isolated from the Heterorhabditis nematodes collected from various parts of India by injecting different concentrations of bacterial cells into fourth instar larval stage of insect Galleria mellonella. Photorhabdus luminescens ssp. akhurstii strain IARI-SGMG3 from Meghalaya was identified as the most virulent of all the tested strains on the basis of LT₅₀ and LC₅₀ values. This study forms a basis for further investigations on the genetic basis of virulence in Photorhabdus bacteria.     

A new species of the jewel-beetle subgenus <Emphasis Type="Italic">Acmaeodera</Emphasis> (<Emphasis Type="Italic">Ptychomus</Emphasis>) Marseul, 1866 from Oman (Coleoptera,Buprestidae: Polycestinae: Acmaeoderini)

A new species of buprestid beetles, Acmaeodera (Ptychomus) koshtali sp. n. (Coleoptera: Buprestidae: Polycestinae) from Oman is described, illustrated, and compared with the closely related species A. (P.) arabica Gory, 1840 and A. (P.) sancta Théry, 1926 which are also recorded from the Arabian Peninsula.     

Two new feather mites of the genus <Emphasis Type="Italic">Proctophyllodes</Emphasis> Robin, 1868 (Acari: Proctophyllodidae) from European passerines (Aves: Passeriformes)

Two new species of the feather mite genus Proctophyllodes Robin, 1868 (Analgoidea: Proctophyllodidae) are described from two passerine birds (Passeriformes) in Europe: Proctophyllodes markovetsi n. sp. from the tawny pipit Anthus campestris (L.) (Motacillidae) and P. loxiae n. sp. from the red crossbill Loxia curvirostra (L.) (Fringillidae). Males of P. markovetsi are most clearly distinguished from the closely related P. tchagrae Atyeo & Braasch, 1966 by having greater terminal lamellae (30–40 × 20–25 µm), the tips of genital arch curved medially, and the corolla of the anal sucker with 14–15 denticles; females of this species are characterised by the terminal appendages distinctly longer than the lobar region width. Males of P. loxiae differ from the closest species, P. fuchsi Mironov, 1997, by having smaller terminal lamellae (45–50 × 22–28 μm), the genital organ extending beyond the posterior margin of lamellae by half their length; females can be distinguished by having the terminal cleft noticeably wider than long (28–30 × 35–40 μm).     

Pre-harvest aflatoxins and <Emphasis Type="Italic">Aspergillus flavus</Emphasis> contamination in variable germplasms of red chillies from Kunri,Pakistan

Various cultivars of red chilli were collected from a small town named Kunri, located in the province Sindh, Pakistan. This town is a hub of red chilli production in Asia. A total of 69 samples belonging to 6 cultivars were obtained and analysed for the occurrence of aflatoxins and Aspergillus flavus, to explore the potential of resistant and susceptible germplasm. Aflatoxins were detected by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), while A. flavus was isolated and identified using agar plate, blotter paper, deep freezing and dilution techniques. Molecular characterization using internal transcribed spacer (ITS) 1/4 and A. flavus specific FL1-F/R primers confirmed the identity of A. flavus. The data revealed that 67 and 75% samples contaminated with aflatoxin B₁ (AFB₁) and with A. flavus, respectively. A highly susceptible chilli cultivar was ‘Nagina’, showing 78.8% frequency of total aflatoxins (1.2–600 μg/kg) and a mean of 87.7 μg/kg for AFB₁ and 121.9 μg/kg for total aflatoxins. A. flavus was detected with 93% frequency and 2.14 × 10⁴ colony forming units. In contrast, cultivars ‘Kunri’ and ‘Drooping Type’ were found to be resistant, with low levels of aflatoxins and fungal counts. The study was conducted for the first time to explore two potential cultivars that were less susceptible towards A. flavus and aflatoxin contamination. These cultivars could be preferably cultivated and thereby boost Pakistan’s chilli production.