Life history and taxonomy of two populations of ligulate Desmarestia (Phaeophyceae) from Chile

1986 ◽  
Vol 64 (12) ◽  
pp. 2948-2954 ◽  
Author(s):  
M. E. Ramirez ◽  
D. G. Müller ◽  
A. F. Peters

Two populations of broad-bladed (ligulate) Desmarestia from central and southern Chile were studied in laboratory cultures. They differ in sporophyte morphology and gametophyte characters (monoecism versus dioecism). The dioecious population is found to be related to D. firma from South Africa and D. munda from the northeast Pacific, while the taxonomic status of the broad-bladed monoecious population is left undetermined. In both populations sporophytes originate after fertilization as well as by apomixis. Chromosome numbers alternate between ca. 23 and ca. 46. Evidence is presented that spermatozoids of the dioecious Desmarestia can develop into sporophytes (androgenesis or ephebogenesis).

1952 ◽  
Vol 43 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Wendell F. Sellers

Collections of Cactophagus spinolae (Gylh.) were made in Mexico in 1946, 1947, and 1948 to supplement the biological control of prickly pear (Opuntia spp.) in South Africa. During these three years, 862, 1,396, and 15,584 adults, respectively, were dispatched to South Africa. The weevils were sent by air express in specially designed containers, and arrived in excellent condition.This paper includes information on the distribution, life history and food preferences of C. spinolae. The need is stressed for anticipating the effects of transit conditions upon living insect material transported by aircraft.


2008 ◽  
Vol 29 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Carissa Jones ◽  
Isaac Rojas-González ◽  
Julio Lemos-Espinal ◽  
Jaime Zúñiga-Vega

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.


Koedoe ◽  
2004 ◽  
Vol 47 (1) ◽  
Author(s):  
R.F. Terblanche ◽  
H. Van Hamburg

Due to their intricate life histories and the unique wing patterns and colouring the butterflies of the genus Chrysoritis are of significant conservation and aesthetic value. Thisoverview probes into practical examples of butterfly life history research applicable to environmental management of this relatively well-known invertebrate group in South Africa. Despite the pioneer work on life histories of Chrysoritis in the past, more should be done to understand the life history of the butterflies in the wild, especially their natural host plants and the behaviour of adults and larvae. A system of voucher specimens of host plants should be introduced in South Africa. Although various host plant species in nature are used by the members of Chrysoritis, including the Chrysoritis chrysaor group, the choice of these in nature by each species is significant for conservation management and in the case of Chrysoritis aureus perhaps even as a specific characteristic.A revision of the ant genus Crematogaster will benefit the conservation management of Chrysoritis species since some of these ant species may consist of a number of specieswith much more restricted distributions than previously thought. Rigorous quantified tudies of population dynamics of Chrysoritis butterflies are absent and the introductionof such studies will benefit conservation management of these localised butterflies extensively.


2017 ◽  
Vol 9 (3) ◽  
pp. 404-413
Author(s):  
Abolade Oluremi BOLAJI ◽  
Julius Olaoye FALUYI

Morphological, anatomical and chromosome studies of Hyophila crenulata C, Mull. Ex Dus, Thuidium gratum (P. Beauv) Jaeg., Barbula lambarenensis P. Vard.. Stereophyllum nitense Mitt. and Bryum coronatum Schwaegr from Nigeria, were carried out with a view to bridging some knowledge gaps that exist in their characterization and providing insightful information that could be useful in elucidating their taxonomic status. The morphological and anatomical studies revealed several gametophytic and sporophytic attributes which have not been previously reported and which were diagnostic for the moss species studied. The chromosome studies revealed the chromosome numbers to be Hyophila crenulata n = 4; Thuidium gratum n = 12 (10 + 2 m); Barbula lambarenensis n = 3; Stereophyllum nitense n = 9; and Bryum coronatum n = 10. The study concluded that the details of the morphological and anatomical descriptions as well as the chromosome numbers being reported for the first time in this study for the moss species studied could be very useful in their identification and taxonomic delimitation.


1988 ◽  
Vol 120 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Norma E. Sanchez ◽  
Jerome A. Onsager

AbstractA combination of published techniques provided point estimates of life history parameters for two natural field populations of Melanoplus sanguinipes (F.) in crested wheatgrass pastures. Stage-specific survival rates averaged 0.4798, 0.2261, 0.7628, and 0.6903 for egg, instars I–III combined, instar IV, and instar V, respectively. Daily survival rates of adults averaged 0.9702, but were slightly lower for females than for males. Estimated duration of nymphal instars averaged 8.4 days, the adult preoviposition period averaged 13.3 days, and adult longevity averaged 26.7 and 36.3 days in the two populations. Oviposition rates were estimated for up to four successive ovipositions, and net replacement rates of populations also were estimated. Neither population replaced itself, indicating that potential capacities for increase were not approached under conditions of these studies.


1992 ◽  
Vol 13 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Y.M. Herselman ◽  
J.H. Van Wyk ◽  
P. le F.N. Mouton

AbstractTo evaluate the taxonomic status of the races of the graceful crag lizard, Pseudocordylus capensis, geographical variation in 44 external morphological characters was determined, using 97 specimens from 31 localities. Two different epiphenotypes predominate in the northern and southwestern parts of the distribution range. These epiphenotypes are, however, connected by a continuum of variation. It is therefore suggested that the recognition of races be abandoned in the formal taxonomy. Several new distribution records for the species are provided.


Zootaxa ◽  
2018 ◽  
Vol 4403 (2) ◽  
pp. 307 ◽  
Author(s):  
OLIVIER S. G. PAUWELS ◽  
ROMAN A. NAZAROV ◽  
VLADIMIR V. BOBROV ◽  
NIKOLAY A. POYARKOV

Based on genetic, morphological and chromatical comparisons we evaluate the taxonomic status of two southern Vietnamese forest-dwelling populations of the Cyrtodactylus irregularis species complex. We confirm the allocation of the population from Binh Chau—Phuoc Buu Nature Reserve (Ba Ria—Vung Tau Province) to C. cattienensis and we describe the population of Nui Chua National Park (Ninh Thuan Province) as Cyrtodactylus sangi sp. nov. This brings to 18 the number of species within the C. irregularis complex and to 41 the number of described Cyrtodactylus species recorded from Vietnam. 


Bothalia ◽  
1977 ◽  
Vol 12 (2) ◽  
pp. 313-317 ◽  
Author(s):  
Éva Kovács-Endrődy

The genus Rubidgea Tate of the fossil family Glossopteridaceae was reduced to a synonym of Glossopteris by Seward (1907). Seward’s conclusion is now confirmed by a study of a wide range of imprints from a quarry near Hammanskraal, South Africa. The upper and lower surface imprints of a single leaf found on a split fragment of carbonaceous shale provides the main evidence presented. The finely striated upper surface imprint of the leaf could be identified with  Rubidgea, whereas the lower surface imprint represents the typical strong venation of a  Glossopteris. The type species of  Rubidgea is transferred to  Glossopteris as  G. mackayi (Tate) Kovacs comb. nov. The characteristics of upper and lower surface imprints of a number of  Glossopteris species are discussed.


Bothalia ◽  
1997 ◽  
Vol 27 (1) ◽  
pp. 75-82 ◽  
Author(s):  
J. J. Spies ◽  
S. M. C. Van Wyk ◽  
I. C. Nieman ◽  
E. J. L. Liebenberg

This is a report on chromosome numbers for the tribe Poeae, which is represented in South Africa mainly by naturalized exotics. Chromosome numbers of 67 specimens, representing 26 species and 11 genera, are presented. These numbers include the first reports on Poa binata Nees (n = 3x = 21 and n = 4x = 28), Puccinellia acroxantha C.A.Sm. CE.Hubb. (n = 3x = 21) and P. angusta (Nees) C.A.Sm. C.E.Hubb. (n = x = 7). New ploidy levels are reported for Catapodium rigidum (L.) CE.Hubb.(n = 2x = 14), Festuca caprina Nees (n = 2x = 14) and F. scabra Vahl (n = x = 7).


2003 ◽  
Vol 25 (1) ◽  
pp. 41 ◽  
Author(s):  
JM Macaranas ◽  
D Colgan ◽  
S Ingleby

The taxonomic status of fruitbats belonging to the genera Nyctimene and Rousettus from the Solomon Islands was investigated using allozyme electrophoresis. Two populations from the Bismarck Archipelago (Papua New Guinea) were included as reference profiles. The allozyme data at 23 loci assigned all specimens into either Nyctimene albiventer or Nyctimene major. The N. albiventer specimens comprised two subspecies, N. a. papuanus from the Bismarck Archipelago and N. a. bougainville from the Solomon Islands. No support was evident for bougainville being a separate species, and indeed the data suggest that N. a. bougainville encompasses the previously described species N. malaita and subspecies N. a. minor. Genetic distances between populations of R. amplexicaudatus from the Bismarck Archipelago and the Solomon Islands were generally low, supporting recent morphological assessments that the subspecies hedigeri, from the majority of the Solomon Islands, should be considered synonymous with subspecies brachyotis. An individual from Choiseul (Solomon Islands) with a distinctive allozyme profile is the only evidence of taxonomic complexity in R. amplexicaudatus.


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