Seed germination of four Jordanian Stipa spp: differences in temperature regimes and seed provenances

Stipa steppes are considered to be an important model ecosystem in arid land ecology owing to their wide geographical distribution and their strong association with human activities. This paper presents data on the seed germination of four Jordanian Stipa species ( Stipa capensis, Stipa parviflora , Stipa arabica and Stipa lagascae ) that are widespread throughout various phytogeographical regions in Jordan. We studied variation in seed germination under laboratory conditions among populations and under various temperature regimes. There was significant variation in seed germination with temperature in all four species and seed provenance was significant for three out of the four species. The temperature levels that were most suitable for germination varied from low (8/4°C and 20/10°C) for S. lagascae to high (20/10°C and 32/20°C) for S. capensis ; S. arabica and S. parviflora germinated equally well at all three temperature regimes. Variations among populations were species specific, but populations with the highest seed germination were always of arid and Saharan Mediterranean origin. Thus, seed germination was negatively correlated with annual precipitation. Such flexibility among temperatures and populations could be interpreted as an efficient survival strategy for species growing under unpredictable environmental conditions. Where artificial reseeding is necessary, differences among species and also among different seed provenances should be taken into account.     

Bidirectional introgressive hybridization between Lepus capensis and Lepus yarkandensis

Lepus capensis and Lepus yarkandensis are two well-established hare species with different habitat preferences and obvious morphological distinctions. L. capensis is common and widespread while L. yarkandensis is an endemic species with a restricted distribution in the Tarim Basin of western China. During field sampling, individuals with a distinct phenotype were found in the contact zone between the two species. To understand the origin of these unclassified individuals, we analyzed morphological and genetic data from 700 individuals including L. yarkandensis, L. capensis and the unclassified individuals. Morphological analyses of the unclassified individuals revealed that they lie between L. yarkandensis and L. capensis. Genetic analyses based on species-specific molecular markers (mitochondrial control region and SRY) showed that the unclassified populations have mtDNA and SRY genes from both L. capensis and L. yarkandensis, suggesting that the unclassified populations result from hybridization between the two species. Interestingly, many identical and/or very similar mtDNA haplotypes were shared between L. capensis populations and L. yarkandensis populations close to their contact zones, which further suggests the existence of extensive bidirectional mtDNA introgression. Similarly, we found evidence for SRY introgression, though it existed at a lower level compared to mtDNA introgression.     

The phylogenetic position of Haasiella (Basidiomycota, Agaricomycetes) and the relationships between H. venustissima and H. splendidissima

Based on a combined ITS-LSU rDNA analysis, the omphalinoid genus Haasiella is shown to be part of the Hygrophoroid clade and sister to Hygrophorus. H. venustissima and H. splendidissima are conspecific; H. splendidissima is the tetrasporic/clamped and heterothallic form of H. venustissima.     

Molecular identification and barcodes for the genus Nymphaea

Nymphaea species, the most popular decorative plants, were collected for specificity of inter-simple sequence repeat (ISSR) analyses in species identification and differentiation of cultivars and natural populations. Dendrogram constructed from ISSR analyses separated out wild species, namely Nymphaea cyanea, N. nouchali, N. capensis, N. lotus and an outgroup N. mexicana, and cultivars. The dendrogram indicates that the cultivars should be differentiated from N. capensis, as they are sister individuals of N. capensis. The ISSR banding data and the dendrogram are concordantly concluded that wild N. capensis would be an effective type species for producing different cultivars. After plant identification by ISSR markers, DNA barcodes of all sample materials were done to provide species specific markers which can be used for rapid and accurate further plant identification without morphological characters. DNA barcoding sequence analysis indicates genetic distance values. All sequences were recorded in GenBank database.     

Cryptic species of rockfishes (Sebastes: Scorpaenidae) in the southern hemisphere inferred from mitochondrial lineages.

We used mitochondrial DNA sequence variation of Sebastes from the southeastern Pacific and three localities in the South Atlantic to address long-standing systematic and evolutionary issues regarding the number of species in the Southern Hemisphere. Sequences of the hypervariable mitochondrial control region were obtained from 10 specimens of S. capensis from South Africa (n = 5) and from Tristan da Cunha Island (n = 5) and 27 of S. oculatus from Valparaiso, Chile (n = 10), and the Falkland Islands (n = 17). Results of the study include (1) significant levels of genetic differentiation among the sampled populations (phi ST = 0.225, P < .000001), thus indicating limited gene flow; (2) corroboration of the existence of two different lineages of austral Sebastes corresponding to S. capensis and S. oculatus; (3) finding that S. capensis is not restricted to Tristan da Cunha and South Africa, but is widespread across the South Atlantic; (4) the position of S. capensis as the ancestral lineage of the austral Sebastes; (5) the existence of a third evolutionary lineage with high levels of genetic divergence, particularly abundant in the south-western Atlantic, which may be recognized as a third austral species of Sebastes.     

Flies (Diptera: Muscidae: Calliphoridae) are efficient pollinators of Allium ampeloprasum L. (Alliaceae) in field cages

In conjunction with efforts to identify efficient insect pollinators for seed multiplication of cross-pollinated plant species stored and maintained by USDA-ARS Western Regional Plant Introduction Station (WRPIS), experiments were conducted to assess and compare the efficiency of the house fly, Musca domestica L. (Diptera: Muscidae), and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae), and different densities of each fly species, to pollinate leek, Allium ampeloprasum L., plant inventory (PI) accessions in field cages for seed yield maximization and high germination. Cages with flowering plants were exposed to 0 flies or stocked with 100, 250, and 500 M. domestica or C. vicina pupae per week for 6 (2002) and 7 (2004) wk. Seed yield (weight per cage) increased linearly as fly densities (C. vicina or M. domestica) increased from 0 to 500 pupae per week, with 500 fly cages averaging 340.7 g (C. vicina) and 70.5 g (M. domestica) of seed in 2002 (PI 368343) and 615.3 g (PI 168977) and 357.5 g (PI 368343) in 2004 when only the C. vicina was used. For 0, 100, and 250 fly cages, seed yields averaged between 2.3 and 175.3 g in 2002 and 10.7 and 273.1 g in 2004. Mean 100-seed weights between treatments ranged narrowly between 0.4 and 0.5 g in 2002 and 0.3 and 0.4 g in 2004, and germination rates of seed lots from "fly cages" were mostly > or =80% in both years. The C. vicina is an efficient and cost-effective pollinator ($388.97 for pupae and shipping, compared with $2,400 for honey bee, Apis mellifera L. [Hymenoptera: Apidae], nuclei) for caged leek accessions, with 250 and 500 C. vicina pupae per week required to produce sufficient seed (130 g) to fill an accession storage bag in the WRPIS gene bank.     

Phylogeography of the Cape velvet worm (Onychophora: Peripatopsis capensis) reveals the impact of Pliocene/Pleistocene climatic oscillations on Afromontane forest in the Western Cape, South Africa

Habitat specialists such as soft-bodied invertebrates characterized by low dispersal capability and sensitivity to dehydration can be employed to examine biome histories. In this study, the Cape velvet worm (Peripatopsis capensis) was used to examine the impacts of climatic oscillations on historical Afromontane forest in the Western Cape, South Africa. Divergence time estimates suggest that the P. capensis species complex diverged during the Pliocene epoch. This period was characterized by dramatic climatic and topographical change. Subsequently, forest expansion and contraction cycles led to diversification within P. capensis. Increased levels of genetic differentiation were observed along a west-to-south-easterly trajectory because the south-eastern parts of the Cape Fold Mountain chain harbour larger, more stable fragments of forest patches, have more pronounced habitat heterogeneity and have historically received higher levels of rainfall. These results suggest the presence of three putative species within P. capensis, which are geographically discreet and genetically distinct.     

Influence of host size and sex on the endohelminth infracommunities of the red rockfish Sebastes capensis off Northern Chile

The relationship between host size and sex and the abundance, prevalence, species richness, diversity, and total number of parasites in the infracommunities of Sebastes capensis was analyzed. Nine helminth species were obtained from 180 red rockfish captured off Coquimbo Bay, Northern Chile. These included the digeneans Pseudopecoelus sp., Diphtherostomum sp., Derogenes sp., Podocotyloides sp., and Lecithochirium sp., the acanthocephalan Corynosoma sp., and the nematodes Ascarophis sebastodis, Hysterothylacium sp., and Anisakis sp. The abundances of Pseudopecoelus sp. and Anisakis sp. were significantly and positively correlated with the size of S. capensis, while Corynosoma sp. correlated negatively with host size. Only prevalence of Anisakis sp. increased with host size. The number of parasite individuals increased significantly with size of S. capensis. However, species richness and diversity of the infracommunities was not affected by host size. These results suggest that red rockfish > 18 cm do not undergo significant ontogenetic changes in their diet. Host sex did not seem to affect abundance and prevalence of infections. The presence of Derogenes sp. and Podocotyloides sp. are new records of digeneans for S. capensis.     

Age structure and abundance in populations of muscoid flies from a poultry facility in Southeast Brazil

Muscina stabulans, M. domestica, Chrysomya putoria, C. megacephala and Stomoxys calcitrans were the most abundant muscoid flies captured in a poultry facility in southeastern Brazil. We examined the gonadotrophic profiles of the females caught at different sites and different times and found that Mu. stabulans and M. domestica, the predominant species, presented similar gonadotrophic profiles only when captured on the manure under the cages, but very different and sometimes opposite gonadotrophic profiles when sampled from wooden posts, vegetation or electric cords. We also determined sex ratios and relative abundance for these two species and found significant differences between them. More than 50% of the females of both species of Chrysomya captured on manure carried eggs or exhibited signs of recent oviposition. The vast majority of S. calcitrans presented ovaries with eggs or signs of recent oviposition. A small proportion of them had ovaries in the recent emerged condition. Our data on ovarian stages, sex ratio and relative abundance allowed us to associate different gonadotrophic profiles with each site and characterize each site as a resting, ovipositing or mating site.     

Mitochondrial DNA analyses of the Cape hakes reveal an expanding, panmictic population for Merluccius capensis and population structuring for mature fish in Merluccius paradoxus

The Cape hake species, Merluccius capensis and Merluccius paradoxus are the most important resource of the South African and Namibian demersal fishery, but it is unclear whether there is a single population of each shared by both countries. We analysed the population structure and evolutionary history of these two species using the variable 5' region of the mtDNA control region for 311 specimens of M. capensis and 333 specimens of M. paradoxus sampled between Lüderitz (southern Namibia) to south of Cape Point (South Africa). 107 haplotypes for M. capensis and eight haplotypes for M. paradoxus were recovered. AMOVA and pairwise Phi(st) analyses revealed no structure in M. capensis, however significant genetic differentiation between Namibian and South African 'populations' was detected for M. paradoxus. This was only restricted to mature fish older than 3 and 4 years and not for juvenile fish younger than 3 years. Analyses reveal that M. capensis has undergone population expansion (Fu's Fs=-26.65, P<0.001), possibly within the last 4500-23,000 years, whereas M. paradoxus has not. Our study highlights the utility of genetic markers to unravel the evolutionary history of sympatric species, as well as addressing management issues within regions where commercially valuable fish stocks are shared between nations.     

Ornithodoros (Alectorobius) spheniscus n. sp. [Acarina: Ixodoidea: Argasidae: Ornithodoros (Alectorobius) capensis group], a tick parasite of the Humboldt penguin in Peru

Ornithodoros (Alectorobius) spheniscus n. sp., described from wild-caught and laboratory-reared females, males, nymphs, and larvae parasitizing the Humboldt Penguin, Spheniscus humboldti Meyen, is the fifth species of the Ornithodoros (Alectorobius) capensis group to be recognized in the Neotropical Region. A related Peruvian species, Ornithodoros (Alectorobius) amblus Chamberlin, also parasitizes S. humboldti but is recorded from a wider range of marine birds breeding on the Pacific coast and offshore islands, where the birds congregate to feed on the rich fish fauna usually produced by the Humboldt current. Differential criteria are provided for the new species, O. (A.) amblus, and Ornithodoros (Alectorobius) yunkeri Keirans, Clifford, and Hoogstraal of the Galapagos. These 3 members of the O. (A.) capensis group parasitize marine birds associated with the Humboldt current in western South America and the Galapagos. Persons visiting Humboldt Penguin breeding sites in caves and on barren coastal ledges are eagerly attacked by nymphal and adult O. (A.) spheniscus and suffer afterward from pruritus and slowly-healing blisters. The O. (A.) spheniscus life cycle required 128 to 193 days in the laboratory and, as typical of bird-parasitizing members of the subgenus Alectorobius, the first nymphal instar did not feed.     

Mitochondrial sequence variation in Carlos capensis (Neumann), a parasite of seabirds,collected on Torishima Island in Japan

Partial mitochondrial 16S ribosomal ribonucleic acid gene sequences in the ticks Carios capensis collected from black-footed albatross. Diomedea nigripes, colonies on Torishima Island, Japan (30 degrees 28'N, 140 degrees 18'E), were examined. The sequence was compared with those of C. capensis from Hawaii, South Carolina, and Texas. The sequences were all identical in ticks from Torishima and 2 from Hawaii. There were 2-3 transitions between the other Hawaiian and Texas ticks and Torishima specimens. Two transitions were also observed when compared with the ticks from South Carolina. The results suggest the possibility of gene flow between tick populations at each of the 2 geographic sites, which probably was accomplished by tick-infested migratory seabirds at their breeding sites. Sequence comparison analysis indicated that the C. capensis ticks are on the branch with C. marginatus and C. mexicanus ticks and not with Ornithodoros. This supports the revision suggested by Klompen and Oliver (1993).     

Weight gain of the predator Podisus distinctus (Heteroptera: Pentatomidae) with combinations of the preys Tenebrio molitor (Coleoptera: Tenebrionidae) and Musca domestica (Diptera: Muscidae)

Little is known about Podisus distinctus (Stal) (Heteroptera: Pentatomidae) one of the Asopinae species with good possibilities for mass rearing and releasing against defoliator caterpillars in eucalyptus reforested areas in Brazil. We evaluated the impact of prey combinations on weight of nymphs and adults of P. distinctus. The prey were Musca domestica L. (Diptera: Muscidae) and Tenebrio molitor L. (Coleoptera: Tenebrionidae). The experiment was developed under 25 +/- 0.5 degrees C, 60 +/- 10% R.H. and photophase of 14 hr, with nymphs of P. distinctus individualized in Petri dishes and fed as: T1-larvae of M. domestica during its whole nymphal phase: T2-larvae of M. domestica during its II instar and of T. molitor during the other instars: T3-larvae of M. domestica during II and III instars and of T. molitor during the other instars: T4-larvae of M. domestica during II, III and IV instars and of T. molitor during the V instar; T5- larvae of T. molitor during all instars. P. distinctus presents lower weight when fed with larvae of M. domestica. For this reason it is recommended to feed P. distinctus with T. molitor during its whole nymphal phase or with larvae of M. domestica only during II and III instars and T. molitor during IV and V instars.     

Age and growth of the soldier, Sebastes capensis (Pisces: Scorpaenidae) at Tristan da Cunha and Gough Island, South Atlantic Ocean

Age and growth in the scorpaenid Sebastes capensis was studied at Tristan da Cunha and Gough Island using otoliths. The growth rate of specimens collected at Gough Island was almost twice that of specimens collected at Tristan da Cunha. The largest specimen from Tristan was aged at 18 years while similar-sized fish from Gough were only 11 years old. Because the populations at the two localities were not considered to be genetically isolated from one another, it was hypothesized that the difference in the growth rate and longevity was related to site-specific environmental conditions. Inshore sea temperatures were, on average. 3°C higher at Tristan than at Gough throughout the year. It is concluded that this temperature difference may affect growth rate indirectly through regulating diet and metabolic activity in S. capensis. Changes in reproductive strategy related to the level of environmental predictability at the two localities may also affect growth rate in this species.     

Inermicapsifer beveridgei n. sp. (Cestoidea: Anoplocephalidae) from Procavia capensis (Hyracoidea) in Israel, with notes on two species of Hymenolepis

Inermicapsifer beveridgei n. sp. from Procavia capensis differs from all other species in the genus in having 150-174 testes per segment. The closest species is I. hyracis (Rudolphi, 1810) Janicki, 1919, with 75-120 testes. Hymenolepis vogeae Singh, 1956 and H. horrida (Linstow, 1901) Lühe, 1910, are briefly discussed.     

Spatial and temporal predictability of the parasite community structure of a benthic marine fish along its distributional range

The search for consistent patterns of organisation in parasite communities remains a central theme in parasite community ecology. However, to date, much evidence comes from studies without replication in both space and time; when replicate communities are examined, repeatable patterns are rarely observed. Here we determine, using nested subset analyses, whether the infracommunities of ectoparasites and endoparasites of a benthic marine fish (Sebastes capensis) show non-random structure. Then we examine the spatial repeatability of parasite community structure across the host's distribution in the southern Pacific, and the temporal repeatability of ectoparasite community structure from one locality. In total, 537 fish were captured from different latitudes (between 11 degrees S and 52 degrees S) along the Pacific coast of South America; a further 122 specimens were captured in two other years from one of the sampling localities, Valdivia (40 degrees S). In spite of variation in fish sizes among samples, fish size generally did not correlate with either ecto- or endoparasite species richness. The ecto- and endoparasite species richness of the component communities were also not correlated with fish sample size across the nine localities. Significant nested patterns were found in the ectoparasite communities of S. capensis at all eight localities, except at latitude 52 degrees S. Significant nested patterns were also found in the endoparasite infracommunities of S. capensis at seven of the nine localities, the exceptions being those from latitudes 11 degrees S and 20 degrees S. On a temporal scale, significant nestedness was observed in the ectoparasite infracommunities of S. capensis during each of the 3 years of sampling at Valdivia. In general, the same parasite species are responsible for the repeatability of nested patterns, though their importance varies among localities. The spatial and temporal predictability of the parasite community structure in S. capensis may be associated with the fish's benthic habitat and territorial behavior, suggesting that host biology may be a key determinant of the structure of parasite communities.     

A revision of Centella series Capenses (Apiaceae)

Centella capensis (L.) Domin and related species form a distinct but poorly known group within the genus. The most conspicuous diagnostic feature is the unique inflorescence structure. Each umbel comprises a central umbellule reduced to a single, sessile, functionally female flower and four lateral, functionally male, pedicellate umbellules each reduced to a single flower. The umbel is surrounded by four large, foliaceous bracts. Another unusual character is the habit. Most of the species are annuals or short-lived perennials, while all other species of the genus are perennial shrublets. A taxonomic revision of the four species and three varieties recognized, is presented.     

Sexual dimorphism, reproductive biology, and food habits of two species of African filesnakes (Mehelya, Colubridae)

The ecology and general biology of African snakes remains virtually unstudied, even in highly distinctive species such as the filesnakes (genera Mehelya and Gonionotophis ). Our measurements and dissections of preserved specimens provided information on body sizes, sexual dimorphism in size and bodily proportions, clutch sizes, and food habits of two Mehelya species. In both M. capensis and M. nyassae , females attain sexual maturity at the same size as conspecific males, but grow to much larger sizes. Mehelya capensis displays extreme differences in body shape between males and females at the same body length: females have longer and wider heads, thicker bodies, and larger eyes (relative to both head length and head width) than do conspecific males. Dimorphism in body proportions is less marked in M. nyassae. Female reproductive cycles are seasonal in M. capensis , and clutch sizes are larger in this species than in its smaller congener (5-11 eggs in M. capensis , 2-6 eggs in M. nyassae ).
Contrary to popular wisdom, Mehelya are not specialized ophiophages. Mehelya nyassae feeds primarily upon lygosomatine skinks, including many fossorial taxa. Mehelya capensis has a broader diet, feeding on a wide variety of terrestrial lizards (especially agamids and gerrhosaurids) and snakes. Toads are also common prey items. The diversity of prey types taken by M. capensis suggests that these snakes may use ambush predation as well as active foraging. Mehelya is strongly convergent with Asian elapids of the genus Bungarus in its morphology (triangular body shape; powerful jaws; visible interstitial skin), behaviour (nocturnality; reluctance to bite when harassed), and diet (feeding on elongate reptiles, including snakes). Observations of preyhandling and ingestion by captive snakes are needed to clarify possible selective forces for the evolution of the unusual traits shared by these taxa.