Demography of a population of Moina micrura kurz (Crustacea: Cladocera) in a temporary pond,peninsula of paraguaná, Venezuela

A population of M. micrura Kurz from a shallow, muddy and temporary pond, located in Peninsula of Paraguaná, western Venezuela, was studied from filling to drying phase. Population density, age structure, fecundity, and length of females, were determined. This population showed a low population density (< 50 ind/1), a low and density-dependent fecundity (mean eggs/adults = 1.3; mean clutch size = 2.1 eggs + embryos), and low juveniles to adults ratio (0.71). No significant correlation was detected between mean clutch size and mean body length of ovigerous females. Our results suggest effects of food limitations, and fish predation on demographic parameters of this population. Still, in unfavourable conditions, some demographics features associated to opportunistic species were evident.     

Molecular taxonomy and population structure of the rough‐toothed dolphin Steno bredanensis (Cetartiodactyla: Delphinidae)

Several delphinid species have shown genetic population structure, both between and within ocean basins. We investigated genetic differentiation in the rough‐toothed dolphin, Steno bredanensis, using mitochondrial control region sequences from several localities worldwide (N = 112). Preliminary analyses indicated high levels of genetic differentiation between the Atlantic and Pacific/Indian Oceans, which were further investigated using complete cytochrome b sequences and mitogenomes. Phylogenetic analyses were inconclusive about the existence of cryptic speciation in the genus Steno. Notwithstanding this result, analysis of molecular variance and Φ‐statistics analyses revealed strong population differentiation not only between the Atlantic and Pacific, but also within the Atlantic, where three populations were detected: Caribbean, southeastern Brazil, and southern Brazil. We propose that these populations be considered management units for conservation purposes. Our results provide the first perspective on the worldwide genetic differentiation of S. bredanensis. © 2015 The Linnean Society of London     

Eight polymorphic microsatellite loci for bottlenose dolphin and other cetacean species

We developed eight polymorphic microsatellite loci that can be used to elucidate population structure and aid management of bottlenose dolphins, Tursiops truncatus, in the northwest Atlantic. These loci averaged nine alleles, with no evidence for null alleles. Their cross‐species utility was examined in Cephalorhynchus commersonii, Delphinus delphis, Delphinapterus leucas, Eschrictius robustus, Globicephala macrorhynchus, Lagenorhynchus obliquidens, Orcinus orca, Steno bredanensis and Stenella clymene. On average, 75% of the loci were polymorphic in these species (range = 50–88%). Our results indicate that these loci will be useful for elucidating population structure of bottlenose dolphin as well as of other cetacean species.     

Genetic structure, population size, and seed production of Pulsatilla vulgaris Mill. (Ranunculaceae) in Central Germany

Pulsatilla vulgaris Mill. (Ranunculaceae) is a rare and rapidly declining grassland community species that was once widespread at a time when Central Germany was covered by steppe vegetation. Through the course of this study, the patterns of random-amplified polymorphic DNA (RAPD) variation among 11 populations of varying size were analysed to assess any possible local differentiation, in relation to spatial isolation, resulting from random genetic drift brought on by reduced population size and lack of migration between geographically isolated populations. Following results attained from methods including: multivariate analysis based on asymmetric Soerensen similarity, φ_ST-statistics, and analysis of molecular variance, we were able to conclude that there is a high within-population variability (84.4%) and a weak, but significant, differentiation among populations (φ_ST=0.17). A matrix correlation between genetic and geographical distances revealed that geographical differentiation was reflected in the RAPD profile (Mantel test: r=0.47,p=0.002). Further significant correlations were noted between population size and both percentage of polymorphic loci (p=0.02) and genetic diversity (p=0.03). An additional analysis of seed production showed that mean seed set, seed number, and mean seed mass per population could be attributed to differences in population size, whereas only seed mass was related to genetic variation.     

Segregation by species and size classes of rainbow trout,Salmo gairdneri,and Sacramento sucker,Catostomus occidentalis,in three California streams

Synopsis The hypothesis that Sacramento suckers, Catostomus occidentalis, compete with rainbow trout, Salmo gairdneri, for space in streams was examined by measuring microhabitat utilization of both species in three California streams. Two streams were similar in most respects except one contained only trout and one contained trout and a large population of suckers. The third stream, formed by the union of the first two, contained trout and a small population of suckers. The species overlapped in five of the six microhabitat variables measured: maximum depth, mean water column velocity, focal point velocity, surface water velocity, and substrate type. However, the species had strong vertical segregation; there was little overlap between species in focal point depth. Mean focal point velocities were also significantly different. Suckers roamed over and generally remained in contact with the bottom while trout held position in the water column. Microhabitat utilization by trout in the stream without suckers was similar to in the stream with a higher sucker density. Differences in microhabitat utilization by trout between the third stream and the other two was attributed to the larger size of the third stream. Both sucker and trout showed a similar within-species segregation of size classes - fish under 50 mm in length sought shallow water. Size-specific trends indicated ontogenic shifts in resource utilization which reduced overlap within species. These results suggest that competition for space between trout and suckers was not a major factor regulating microhabitat utilization of trout, although the possibility that larger suckers may displace small trout needs further study.     

Competition between co-dominant plants of the Serengeti plains depends on competitor identity,water, and urine

Kyllinga nervosa (Steud.) and Sporobolus kentrophyllus (K. Schum.) are co-dominant plants of the Serengeti short-grass plains, Tanzania. The plains are characterized by seasonal and sporadic rainfall and currently support in excess of 1.5 million migratory ungulates. The interactive effect of simulated bovine urine and water availability were tested on the competitive interactions of these species in the laboratory. Sporobolus kentrophyllus was a superior competitor to K. nervosa over the tested treatment levels with respect to growth and reproductive effort. Sporobolus kentrophyllus exhibited rapid growth in response to urine addition, leading to a significant species × urine interaction while reduced growth by K. nervosa in response to low water availability explained the significant species × water interaction and is likely explained by K. nervosa's shallow root system. Kyllinga nervosa, however, appears to be more tolerant of low nitrogen conditions based on its similar growth with and without the urine treatment. The effect of intraspecific competition on total biomass was similar for S. kentrophyllus and K. nervosa. Competition resulted in increased size differences (asymmetry) for K. nervosa and for the interspecific competition treatments compared to the size differences observed for plants grown individually (in absence of competition).Total reproductive biomass was reduced most by competition with S. kentrophyllus, irrespective of target species. The water treatment did not influence reproduction while the urine treatment significantly increased reproductive biomass and interacted with target species, competitor species, and yielded a three-way urine × target × competitor species interaction.Results suggest that codominance of these two species in the Serengeti is regulated by water availability, nitrogen input from grazers, and local neighbor identity.     

Distribution,habitat use,and abundance of the endangered franciscana in southeastern and southern Brazil

The franciscana (Pontoporia blainvillei) is endemic to coastal waters from Brazil to Argentina. The species is regarded as one of the most threatened cetaceans in South America due to high bycatch levels. Four management units (FMAs) were defined throughout the species’ range. FMA II includes states along southeastern and southern Brazil, and represents one of the least known units. Recently, genetic analysis proposed that FMA II comprises two distinct populations and its range should be divided into FMA IIa and IIb. In December 2008 and January 2009 aerial surveys were conducted to assess the distribution and to estimate abundance of franciscanas off FMA II. A total of 54 groups were seen (average group size = 2.76, SE = 0.17) in shallow (mean depth = 7.15 m, SE = 7.08) coastal habitats (average distance from the shore = 6.48 km, SE = 6.28). Abundance corrected for perception and availability bias was estimated at 6,827 (CV = 0.26) franciscanas in FMA II, and at 1,915 (CV = 0.32) and 4,353 (CV = 0.24) franciscanas in FMA IIa and FMA IIb, respectively. This study indicates that, at least during the summer, franciscanas aggregate in shallow coastal habitats. Current estimates of incidental mortality in FMA II correspond to 4.4%–7.3% of the estimated stock size, suggesting high, likely unsustainable bycatch.     

Modifications in phytoplankton size structure by environmental constraints induced by regime shifts in an urban lake

Size related changes of phytoplankton biovolume and species composition have been analysed for forward and reverse regime shifts in a shallow, urban, seepage lake. As a consequence of changes in the hydrology, the pelagic switched from a clear water, macrophyte dominated state to a turbid stable phase with an abundant cyanobacterial population. Experimental nutrient reduction forced the system into a recovery phase. Each state change was associated with significant changes in total biovolume, species composition and size structure affecting surface to volume ratios (S/V). Chlorophyll-a content and S/V drastically increased during the early recovering phase due to small cell sized species developing. As expected, state transitions were associated with significant alterations in size structure and composition.     

Phylogeny and evolution of shallow‐water squat lobsters (Decapoda,Galatheoidea) from the Indo‐Pacific

Squat lobsters have a worldwide distribution and are highly visible crustaceans living in a broad range of habitats. In this study, partial sequences of two mitochondrial DNA genes (16S rRNA and COI) and a nuclear gene (H3) were obtained for all but one of the known species of the shallow‐water genera Sadayoshia (Munididae) and Lauriea, Macrothea and Triodonthea (Galatheidae). Lauriea siagiani appeared to be phylogenetically closer to Triodonthea and Macrothea than to other Lauriea species, suggesting the need for taxonomic re‐evaluation of these taxa. All species of Sadayoshia formed a monophyletic group that would have diverged during the Paleogene (around 50 Mya). Our results support the hypothesis that the late Paleogene–Neogene transition was a period of rapid diversification for shallow‐water species of both Galatheidae and Munididae in the Indo‐Pacific region. This is probably related to high tectonic activity among the Eurasian, Philippine Sea, Indo‐Australian and Pacific plates and corresponding changes in distribution of habitats and ocean currents during the late Paleogene. Finally, the tropical south‐west Pacific province is identified as a major diversification centre for shallow‐water squat lobsters, from where species dispersed to other Pacific and Indian Ocean regions.     

Population ecology and juvenile density hotspots of thornback ray (Raja clavata) around the Shetland Islands,Scotland

Elasmobranchs are facing global decline, and so there is a pressing need for research into their populations to inform effective conservation and management strategies. Little information exists on the population ecology of skate species around the British Isles, presenting an important knowledge gap that this study aimed to reduce. The population ecology of thornback ray (Raja clavata) around the Shetland Islands, Scotland, was investigated in two habitats: inshore (50–150 m deep) and shallow coastal (20–50 m deep), from 2011 to 2022, and 2017 to 2022, respectively. Using trawl survey data from the annual Shetland Inshore Fish Survey, the size composition of R. clavata catches was compared between shallow and inshore habitats across 157 trawl sets, and 885 individuals, over the years 2017–2022. Catch per unit effort (CPUE) of R. clavata was significantly higher in shallow than that in inshore areas (ANOVA, F = 72.52, df = 1, 5, p < 0.001). Size composition also significantly differed between the two habitats (analysis of similarities, R = 0.96, p = 0.002), with R. clavata being smaller in shallow areas and juveniles (<60 cm) occurring more frequently. Spatial distribution maps confirmed density hotspots of juveniles in shallow habitats, with repeated use of certain locations consistent over time. The results of this study provide the first evidence for R. clavata using shallow areas for potential nurseries in Shetland, which can inform the IUCN's Important Shark and Ray Area process. Furthermore, this study provides important new population ecology information for R. clavata around Shetland, which may have important conservation implications and be valuable for informing species and fisheries stock assessments in this region.     

A note on group sizes of oribi (Ourebia ourebi, Zimmermann, 1783) from two contrasting sites in Zambia, with and without predation

The oribi (Ourebia ourebi, Zimmermann, 1783) is a small species of antelope widely represented across open grasslands of sub‐Saharan Africa. Although largely territorial, differences in group size and mating systems (monogamy/polygamy), have been linked to habitat conditions and population density. At high population densities, additional males are recruited to assist in territorial defence. Other factors which might impact on group size, include predation threat, especially at low population densities. In this study (1995–98), we recorded group sizes of oribi across two contrasting areas (c. 300 km² each) of Zambia with (Kafue), and without (Bangweulu), large vertebrate predators. A total of 412 groups was recorded across the two sites, with mean sizes of 2.31 (n = 217) at Bangweulu and 2.33 (n = 195) at Kafue. The modal group size was two throughout (range 1–6). Groups were more variable in size and sex composition at Kafue than at Bangweulu, but there was no significant difference in estimates of population density between sites. Mean estimates were 2.02 and 1.90 km^?2 for Bangweulu and Kafue, respectively. Sex ratios (males : females) were biased towards females (1 : 1.72 and 1 : 3.55, respectively) at both sites. Adult males were particularly scarce at Kafue. However, values of density and group size, were both unexceptional for the species. Whilst a modal group size of two is consistent with a monogamous mating system, variations in group composition and size were more difficult to explain. Adult females appeared to retain or recruit additional animals to groups, irrespective of the needs of territorial defence. This suggests that vigilance is an important function of groups on large open plains, especially in the presence of predators. By extension, reversed sexual dimorphism in oribi could reflect increased selection for vigilance duties in females. Predators had no apparent effect on population density, but oribi groups were more variable in size and sex composition in their presence. Adult males may be particularly vulnerable to predation when defending territorial borders at low population densities. However, further work is needed to define group dynamics in this species and to identify causes of mortality amongst adult males.     

Diel vertical migrations of invertebrate predators (Leptodora kindtii ,Thermocyclops taihokuensis, andMesocyclops sp .) in a shallow, eutrophic lake

We studied vertical distribution patterns of three invertebrate predators – Leptodora kindtii, Mesocyclopssp., and Thermocyclops taihokuensis– in a shallow eutrophic lake, Lake Suwa , Japan. From June to October in 2000 and 2001, we collected samples in the lake center in order to examine the vertical distribution patterns and the densities of the predators in the water column during the day (0900) and at night (2330). We also examined phototactic behavior of Leptodora in the laboratory. The three invertebrate predators showed clear migration patterns. Leptodora and Thermocyclops displayed a typical migration, avoiding the surface and maintaining a high abundance in deeper water during the day, and being distributed uniformly during the night. Mesocyclops, on the other hand, showed no clear vertical distribution pattern in the water column. However, Mesocyclops showed higher densities in the water column during the night than during the day. It suggests that they stayed just above the bottom during the day and migrated upward during the night. Leptodora also showed such a density difference between day and night. In the laboratory, Leptodora showed strong negative phototactic behavior. The observed density changes between day and night in Leptodora and Mesocyclops suggests the possible underestimation of their population density by usual sampling methods, and thus the impact of predation on populations of prey zooplankton species may also be underestimated in shallow water bodies.     

Age, growth, maturity, mortality, and yield-per-recruit for annular sea bream (Diplodus annularis L.) from the eastern middle Adriatic Sea

The population dynamics parameters of Diplodus annularis from the eastern middle Adriatic Sea were studied. Total lengths of 1704 specimens ranging from 3.3 to 23.0 cm were obtained from commercial and fishery‐independent catches (2000–2002). The species spawns from April through the end of August, with a peak in May. Overall male to female ratio was 1.00 : 1.05. The species is a rudimentary hermaphrodite in the Adriatic Sea. Total lengths (TL) at 50% maturity were 9.0 cm for males and 10.0 cm for females. These estimated sizes were smaller than the minimum legal landing size (MLS = 15 cm) and greater than the actual minimum landing size (L_c = 7.1 cm) for the bottom trawl net. All specimens sampled were fully mature above 13 cm TL. The oldest individual was 13 years old. Length–weight relationship showed close to isometric growth (b = 3.073). Parameters of the von Bertalanffy growth equation were: L_∞ = 23.95 cm; K = 0.126 per year; t₀ = −1.664 year; r² = 0.896. The low value of total mortality (Z = 0.72) was a consequence of the relatively low rate of natural mortality (M = 0.39) and fishing mortality (F = 0.33). The exploitation ratio was E = 0.46. Estimated parameters and the relative yield‐per‐recruit analysis did not indicate any overexploitation of the species in the study area. However, the estimates include uncertainties and require further confirmation, especially of the natural mortality.     

Demography of Amboseli baboons, 1963–1983

Repeated censuses of a population of yellow baboons (Papio cynocephalus) in Amboseli National Park, Kenya, revealed a decrease from over 2,500 animals in 1963–1964 to 123 individuals in 1979, or from a density of about 73 to 1.8 baboons per km² over a 15-year period. Median group size decreased from 43 in 1964 to 27 in 1979. The largest and smallest groups declined the most; groups near the median have maintained fairly stable size and age distributions. The population seemed to have stabilized by 1983 at approximately 150 animals in six groups (median group size 28; density 2.2/km²). Although baboon population and group size appeared to be stable during 1963–1964, the age distribution and demographic parameters (age-specific mortality and natality for one social group) during that year indicate that the population decline had already started. The rate of population decline was greatest in the 1964–1969 period and remained appreciable during the next 5 years. The decline of the baboon population was paralleled by that of other Amboseli savannah woodland mammalian species and took place during a period of very high mortality of fever trees (Acacia xanthophloea) and extensive invasion of the area by halophytes, a transition brought on by rising ground water and consequent elevation of the soil salinity zone. In this and several other primate populations, mortality of infants and juveniles appears to be the demographic variable most sensitive to environmental change.     

Spatial and Temporal Variation of Cestode Infection and its Effects on Two Small Barbs (Barbus humilis and B. tanapelagius) in Lake Tana, Ethiopia

Pseudophyllidean cestodes as Ligula have a complex life cycle with cyclopoid copepods as first intermediate host, zooplanktivorous fish as second, and piscivorous birds as final host. We studied the effects of diet, season and habitat occupation on the prevalence of plerocercoid larvae of the tapeworm Ligula intestinalis in two closely related small barbs and the effects of the parasites on the barbs life histories in Lake Tana (Ethiopia) during 1 year. In all affected barbs L. intestinalis caused retardation in gonad development, maturation at reduced size and lower absolute fecundity. Infection rate, averaged over all habitats was significantly higher in B. tanapelagius (10%) than in B. humilis (6%). Below a threshold of 48 mm the infection rate was zero for both barbs, this coincided with a very low proportion of copepods in their diets, increasing up to 90 and 55%, respectively, for their largest size class (81–90 mm). The relatively high infection rate in B. tanapelagius is explained by its obligatory zooplanktivorous feeding behaviour, ingesting a relatively high proportion of infected cyclopoid copepods. This is in contrast with B. humilis, which is a polyphagous species, feeding both on zooplankton and benthic invertebrates. Significant seasonal effects in infection rates were observed. In both barb species infection rates were lower during the breeding season. Only for B. tanapelagius a significant negative correlation was observed between rain fall and infection rate, probably caused by an increased turbidity that decreases feeding efficiency on zooplankton. Habitat type had also a significant effect on infection rate. Barbus humilis showed a much higher infection rate in shallow clear water (10%) than in shallow turbid water (3%), whereas B. tanapelagius showed much higher infection rates in the shallow sublittoral (13%) than in the deeper pelagic (7%). Most likely, birds predate more efficiently on barbs in shallow clear waters than in shallow turbid and deep waters.     

Characterization of microsatellite loci in sea urchins (Strongylocentrotus spp.)

We present six dinucleotide repeats that were developed and characterized in Strongylocentrotus droebachiensis and also tested in S. purpuratus. Four of these loci are polymorphic in S. droebachiensis (13–20 alleles, N= 100) and five are polymorphic in S. purpuratus (5–12 alleles, N= 10). We are currently using these markers to investigate the population substructure of shallow water populations of S. droebachiensis in the north Atlantic.     

Range‐wide genetic analysis reveals limited structure and suggests asexual patterns in the rare forb Senecio macrocarpus

Genetic diversity and recombination underlie the long‐term persistence and evolution of species and are strongly influenced by population size, breeding system and plant longevity. Here, we study genetic structure in the rare Senecio macrocarpus in southeastern Australia to guide current conservation practices. Thirteen neutral microsatellite markers and two chloroplast regions were used to survey the 20 known S. macrocarpus populations and one sympatric S. squarrosus population, a morphologically similar species. All markers showed severe excess or deficit of heterozygotes and linkage disequilibrium was significant. Microsatellite markers revealed 100 multi‐locus genotypes (MLGs) from 523 S. macrocarpus individuals and a further 4 MLGs from 27 S. squarrosus individuals. MLGs varied in frequency and distribution. At the extremes, one MLG was found 108 times across the sampling region and 66 MLGs were found once. The MLGs of all 38 seedlings genotyped were identical to their seed parents implying an asexual origin. Chloroplast regions showed little variation within S. macrocarpus but differed from S. squarrosus. Chromosome counts for S. macrocarpus revealed the same ploidy level as S. squarrosus (2n = 6x = 60) and pollen–ovule ratios were typical of erechthitoid Senecio species showing self‐compatibility. Results suggest that establishment of small populations occur primarily from one extensive source population with indications that both apomixis and selfing may be contributing to its reproduction cycle. We suggest that this species may contribute to future evolutionary processes despite limited genotypic variation and restricted distribution. Its conservation will safeguard evolutionary processes that might occur through occasional outcrossing and hybridization events between sympatric species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 256–269.     

Comparisons between the age structures, growth and reproductive biology of two co-occurring sillaginids, Sillago robusta and S. bassensis, in temperate coastal waters of Australia

Sillago robusta and S. bassensis occupy the open sandy areas of the deeper waters (20–35 m) of the inner continental shelf of the lower west coast of Australia. Comparisons were made of their age and size compositions, growth rates, ages and sizes at first maturity, and spawning times. Most S. robusta were less than 3 years old (maximum 7 years), while S. bassensis often reached 7 years of age (maximum 10 years). The maximum length of S. robusta (200 mm) was far shorter than S. bassensis (328 mm), whereas the reverse pertained for the von Bertalanffy growth coeffcient (K), i.e. c. 1.0 v. c. 0.3. Differences in K reflect the fact that c. 80% of the asymptotic length is achieved by S. robusta after 2 years, but not until 6 years of age by S. bassensis. Sexual maturity was reached by up to 50% of S. robusta at the end of their first year of life, and by almost all fish at the end of their second year of life. Most S. bassensis did not reach maturity until the end of their third year of life. In both species, those individuals that reached maturity early, were significantly longer than those that did not reach maturity at the same age. The gonadosomatic indices and proportions of mature gonads, and the numbers of vitellogenic and hydrated oocytes and post-ovulatory follicles, were relatively high in ovaries of both species between December and March. Although both species spawn in these 4 months, some S. bassensis also spawn between September and November and in March and April. In the middle of the spawning period, the ovaries of S. robusta and S. bassensis frequently contained oocytes that ranged widely in size and development, together with post-ovulatory follicles, suggesting that both species are multiple spawners. Juveniles of S. robusta remain in the deeper waters of the inner continental shelf, whereas those of S. bassensis migrate inshore to their nursery areas in surf zones. As S. robusta reaches sexual maturity at an earlier age and smaller size than S. bassensis, it is probably more advantageous for the juveniles of this species to remain in deeper water, and thereby conserve energy for gonadal maturation, rather than migrating into shallow waters for only a very few months.     

Diel and lunar variation in diving behavior of rough-toothed dolphins (Steno bredanensis) off Kauaʻi,Hawaiʻi

Observational studies describe rough-toothed dolphins (Steno bredanensis) actively foraging during the day on epipelagic species. Using data from depth-transmitting satellite tags deployed on nine individuals off Kauaʻi, we investigated diving behavior and the effects of lunar phase and solar light levels on vertical movements. Overall, tagged rough-toothed dolphins primarily used near-surface waters, spending between 83.6% and 93.7% of their time in the top 30 m of the water column. When diving, grand mean, median, and maximum dive depths were 76.9 m, 67.5 m, and 399.5 m, although individuals were in water with depths from approximately 700–1,450 m. Dive rates varied by time of day, being lowest during the day and at dawn and highest at dusk and night. Dives were deepest (M = 133.7 m, SD = 52.6 m, median = 106.5 m) and longest (M = 4.0 min, SD = 0.4 min, median = 4.0 min) at dusk, suggesting dolphins were taking advantage of prey rising to the surface in response to reduced light levels. Lunar phase indirectly affected diving, with deeper and longer dives occurring with increasing illumination. The variations in dive behavior across solar and lunar cycles indicate diving patterns shift based on the distribution of prey.     

Karyotype analysis and new chromosome number reports in <Emphasis Type="Italic">Silene</Emphasis> species (sect. <Emphasis Type="Italic">Auriculatae</Emphasis>, Caryophyllaceae)

Karyotype study was performed in 13 populations of 11 Silene species (sect. Auriculatae L., Caryophyllaceae) growing in Iran. All the species studied showed 2n = 2x = 24 chromosome number supporting the earlier report on S. meyeri, while the chromosome number of S. palinotricha, S. sojakii, S. gertraudiae, S. elymaitica, S. pseudonurensis, S. dschuparensis, S. eriocalycina, S. araratica, S. prilipkoana and S. commelinifolia are new to science. The chromosomes were mainly metacentric or sub-metacentric and their size varied from 1.10 μm in S. pseudonurensis to 7.11 μm in S. dschuparensis. The species studied differed significantly in the total size of the chromosomes, the size of the short arms and the long arms, indicating the role of quantitative genomic changes in the Silene species diversification. They also differ in their karyotype formulae indicating the occurrence of structural changes in their chromosomes. The Silene species were placed in 1A, 2A, 1B and 2B classes of Stebbins karyotype symmetry showing symmetrical karyotypes. Clustering of the species based on karyotype features grouped the species of S. palinotricha, S. prilipkoana, S. commelinifolia, S. eriocalycina, S. meyeri, S. araratica and S. Sojakii together while the species of S. gertraudiae and S. elymaitica showed more similarity and were placed close to each other.