Life history traits of Aphanius ginaonis Holly, 1929 (Cyprinodontidae) and potential risks of extinction in the Geno hot spring (Iran) population

This study presents some traits of the Aphanius ginaonis life history in the Geno hot spring and explains the potential risks of its extinction. Sampling was from March 2009 to February 2010. A total of 61 males and 71 females were measured (total length) and weighed, with data on reproductive biometry also taken. Growth parameters were determined in addition to weight–length relationships: W (t) = 0.012TL^3.42, R² = 0.96 for females and W (t) = 0.0101TL^3.38, R² = 0.94 for males. A. ginaonis females showed an asymptotic total length (TL_∞) of 53.03 mm; the growth coefficient, K (year^?1) 0.15, t₀ (year) 1.01; and natural mortality coefficient M (year^?1) 0.62. In males the value for TL_∞ was 48.83 mm; for K (year^?1) 0.2, t₀ (year) 0.44; and M (year^?1) 0.49. The relationship between absolute fecundity and fish size (total length, body weight or age) showed a strong correlation to body weight. The A. ginaonis population is threatened with extinction – and a co‐management in cooperation with the local population for strong protection measures is urgently needed.     

Aphanius vladykovi,a new species of tooth-carp from the Zagros Mountains of Iran (Osteichthyes: Cyprinodontidae)

Synopsis A new species of tooth-carp, Aphanius vladykovi, is described from the Zagros Mountains of Iran. The new species is uniquely characterised by a high count of lateral line scales and by different pigmentation patterns from its closest, putative relative A. sophiae. It also possesses several meristic and morphometric differences with topotypic A. sophiae. It became separated from a common ancestor with A. sophiae by orogenic events which led to the formation of the Zagros Mountains and the isolation of the upper reaches of the Karun River basin by the development of tangs, narrow passes through the mountains with high water flow and steep gradient which prevent gene flow between lowland and mountain populations of these small fishes.     

Aphanius arakensis, a new species of tooth-carp (Actinopterygii, Cyprinodontidae) from the endorheic Namak Lake basin in Iran

A new species of tooth-carp, Aphanius arakensissp. n., is described from the Namak Lake basin in Iran. The new species is distinguished by the congeners distributed in Iran by the following combination of characters: 10-12 anal fin rays, 28-32 lateral line scales, 10-13 caudal peduncle scales, 8-10 gill rakers, 12-19, commonly 15-16, clearly defined flank bars in males, a more prominent pigmentation along the flank added by relatively big blotches in the middle and posterior flank segments in females, a short but high antirostrum of the otolith that has a wide excisura, and a ventral rim with some small, drop-like processes, and 19 molecular apomorphies (17 transitions, two transversions) in the cytochrome b gene. It was suggested based on the phylogenetic analysis that the new species is sister to Aphanius sophiae from the Kor River and that Aphanius farsicus from the Maharlu Lake basin is sister to Aphanius arakensis plus Aphanius sophiae. A noticeable feature of the Aphanius diversity in Iran is the conservatism of the external morphology as well as morphometric and meristic characters, while distinctive differences are present in genetic characters, otolith morphology, and male color pattern. Transformation of the latter was probably driven by sexual selection.     

Contrbtion to the biology of Zagros tooth-carp, <Emphasis Type="Italic">Aphanius vladykovi</Emphasis> (Cyprinodontidae) in central Iran

We studied some aspects of the biology of the Zagros tooth-carp, Aphanius vladykovi, an endemic and poorly known species from Chahar-Mahall-va-Bakhtiari province in central Iran, by regular monthly collections and direct observation in aquaria over a full year. We collected individuals from Modar-Dokhtar spring of Gandoman region; we preserved some in formalin and transferred some alive to aquaria. The stomach contents consisted mostly of freshwater crustaceans, suggesting a carnivorous habit. The eggs had an average diameter of 1mm and the average absolute and relative fecundity was 415 and 110, respectively. The gonadosomatic ratio and ovary condition suggested that the reproductive season of the species was between late March and June with a peak in early April. The species is euryhaline and eurythermal and prefers neutral to basic waters. It is usually found in well-oxygenated waters, but is tolerant of hypoxia as well.     

The endangered cyprinodont <Emphasis Type="Italic">Aphanius ginaonis</Emphasis> (Holly, 1929) from southern Iran is a valid species: evidence from otolith morphology

Aphanius Nardo, 1827 (Actinopterygii, Cyprinodontidae) is a widely distributed genus in the Mediterranean and Persian Gulf area and includes several endangered species. The otolith morphology in Aphanius is known to represent a valuable tool for the taxonomy, and is also indicative for the genetic diversity of a particular population. The present study focuses on the otoliths of the endangered A. ginaonis (Holly, 1929), which is endemic to the Geno hot spring in southern Iran. The taxonomic status of A. ginaonis has repeatedly been questioned, and some scholars have argued that it merely represents a morphological variation of the widespread A. dispar. We present a comparison of the otolith morphology of A. ginaonis (52 specimens) with that of A. dispar (Rüppell, 1828) from the Mehran River Basin (southern Iran) (17 specimens) and an A. dispar population from the Persian Gulf coast of the United Arab Emirates (32 specimens). Our data obtained from SEM pictures, otolith morphometry and statistical analyses suggest that A. ginaonis represents a valid species. In A. ginaonis individuals with a standard length exceeding 23 mm, the otolith variables length–height and rostrum length represent useful complementary diagnostic characters discriminating this species from other Aphanius species. Besides ontogenetic variation, we found extremely high otolith form variability in A. ginaonis, including some otoliths with a morphology distinctly deviating from the basic morphology type. We hypothesize that these variations may be a result of the artificial introduction of A. dispar into the Geno hot spring during the last years and subsequent hybridisation.     

The scale characteristics of two Aphanius species from southern Iran (Teleostei: Aphaniidae)

Fish scales are morphologically diverse among species, within species, and even among individuals. The present study investigated macro- and micromorphology of the scales between two closely related Aphanius species in southern Iran including Aphanius hormuzensis, collected from Gotab/Mehran River and A. stoliczkanus, from Howba hot sulphuric spring. The results indicated clear interspecific differences in scale macromorphology and microstructures. The scales of A. hormuzensis are characterised by a rounded shape, 7–9 (mean 8.0±0.83) primary radii, and a relatively large focus with oblong shape that positioned centrally on the scale, while the scales of A. stoliczkanus are characterised by a polygonal shape with few spines in posterior region, 8–11 (mean 10.0±0.78) primary radii and a small rounded focus that positioned posterocentraly on the scale. These species are morphologically close but clearly distinguished by their scale morphology and habitat requirements (e.g. water depth and food availability). Therefore, it can be assumed that clear differences in their scale morphology have been resulted by the combination of both genetic and environmental factors.     

Reproductive biology ofFrangula alnus (Rhamnaceae) in southern Spain

Various aspects of the reproductive biology of the perennial hermaphroditeFrangula alnus Mill. were studied in two populations located in the province of Cádiz, southern Spain. Flowering extends from the second week of May to early July. The small, whitegreenish, entomophilous flowers are incompletely protandrous and last 8–10 days, but pollen transfer takes place only on days 1–3. A very weak, pleasant odour along with nectar and pollen attract over 45 insect species, of which 21 are probable pollinators. These are mainlyDiptera but also includeHymenoptera and the unusual (as flower visitors)Mecoptera. Reproduction is exclusively sexual and strictly xenogamous, with pollen transfer depending solely on insect vectors. Although flower morphology and individual flower phenology do not fully prevent self-pollination, and geitonogamy can easily take place, the level of autogamy was negligible. Therefore, some self-incompatibility mechanism is operative in this species. Only 2.8% of open-pollinated flowers set fruit. At the flower level, fruit initiation was apparently limited by availability of cross-pollen, which in turn seemed influenced by the structure of the population. The seed/ovule ratio in ripe fruits was ca. 50%. Predispersal (maternal) reproductive success (percent ovules becoming filled seeds) was 1.42%. For mature individuals this corresponded to ca. 430 to 1560 potential offspring per year.     

Reproductive biology of Apocryptes bato (Gobiidae) in the Payra River,southern Bangladesh

The gobioid fish Apocryptes bato (Hamilton, 1822) is a species of mudskipper found in Bangladesh, India, and Myanmar. The reproductive biology of A. bato including sex ratio, size at sexual maturity, breeding season, fecundity, and condition factor was studied in the Payra River, southern Bangladesh during May 2016 to April 2017. A total of 1,028 specimens (303 males and 725 females) were collected. The overall sex ratio was significantly different from the expected value of 1:1 (male: female = 1:2.39, χ² = 173.23, p < 0.05). Size at sexual maturity was estimated as 4.9 cm standard length. Monthly variations in gonadosomatic index indicate that the main breeding season is from May to December. There was a significant positive correlation of body length and body weight with fecundity. Fulton's condition factor varied in both sexes and was attributed to variations in GSI with maturity. Breeding season was significantly associated with rainfall, but not air temperature. Our findings should improve management and conservation of this fish in the Payra River and surrounding ecosystems.     

Reproductive biology of the southern thorny skate Amblyraja doellojuradoi (Chondrichthyes,Rajidae)

The total lengths (L_T) of 193 males (209–556 mm) and 130 females (275–515 mm) of Amblyraja doellojuradoi, a commercial by‐catch species on the Argentinean continental shelf, which are increasingly retained, were analysed. No sexual dimorphism was observed in the L_T at which 50% of individuals were sexually mature; males matured at 448 mm and females at 411 mm, c. 80 and 82% of maximum L_T. The hepato‐somatic index was similar among sexes, but significantly different between maturity stages, being lower in mature than immature specimens. Males had no seasonal difference in the hepato‐somatic index and females had the lowest index in autumn. The gonado‐somatic index was lower in males than in females and significantly higher in mature than immature specimens of both sexes. Males had the highest index in autumn and females had no seasonal difference. Collectively, these results would indicate that A. doellojuradoi breeds in autumn.     

Reproductive biology of the Mugger Crocodile,Crocodylus palustris,in Iran (Reptilia: Crocodylidae)

A small population of Mugger crocodiles occurs in the southeastern part of Iran, in Sistan & Baluchestan Province, at the westernmost global range of the species. The peak nesting season is May and consequently the eggs hatch in July, but the nesting season can be extended. In four nests found in the wild, 24, 26, 21 and 13 eggs were counted. A 2.2 m long female, which fell in an overflow pond, laid 21 eggs on a concrete surface exposed to the air. A female kept in captivity laid 18 and 25 eggs in two consecutive years. The mean size for the eggs in the last three nests was calculated as 75.7 x 47.7 mm and 91.27 g in weight. The mean total length and weight for 19 hatchlings was 30.47 cm (29.2–33.9 cm) and 84.3 g (66.2 to 90.3 g) respectively. Based on the number of observed hatchlings compared with the clutch size, it seems that hatchlings have a high mortality rate in the early stages after hatching as a result of natural threats.     

Reproductive biology of Metaschistura cristata in northeastern Iran

The study purpose was to investigate the reproductive biology, growth and length‐weight of the Turkmenian crested loach, Metaschistura cristata, in the Radkan River of northeastern Iran. Age and growth are described for 1029 specimens from January 2009 to December 2010. The sex ratio was 1:1. Maximum age, based on opercula readings, was 6⁺ years for both sexes. Specimens ranged in size from 24 to 98 mm total length and weighed from 0.08 to 7.32 g. The length‐weight relationships were described as W = 0.005166 TL^3.225 (R² = 0.97) for males and W = 0.006192 TL^3.125 (R² = 0.97) for females. Growth was expressed in length and the von Bertalanffy growth parameters were estimated as L_∞ = 354.9 mm, k = 0.0038, t₀ = ?26.82 for males and L_∞ = 339.0 mm, k = 0.0043, t₀ = ?24.88 for females. Growth performance indexes were also estimated as Φ′ = 6.17 for males and Φ′ = 6.20 for females. The gonadosomatic index showed that peak reproduction occurred during April and June, with highest average values of 2.1% for males and 25.3% for females in May. Oocyte diameter ranged from 0.09 to 1.58 mm, with a mean value of 0.54 ± 0.42 mm.     

Reproductive biology of gag in the southern Gulf of Mexico

Aspects of the reproductive biology of gag Mycteroperca microlepis in the southern Gulf of Mexico were studied by following seasonal variations in the gonado‐somatic index and through histological examination of gonads. Gag were collected from inshore and offshore waters of the Campeche Bank, Yucatan, Mexico, between April 1996 and December 2001. This species is a protogynous hermaphrodite, and appeared to be depth‐size distributed. The smallest gag (9–49 cm L _F) collected were all juvenile females, and were caught in inshore waters (1–10 m depth), while the largest (49–116 cm L _F), mainly adult females, males and transitionals, were captured in offshore waters (33–167 m depth). Overall the offshore male to female ratio was female‐biased (1 : 3·3) and differed significantly from unity. The species spawns at depths of c . 50–53 m, from early winter to mid‐spring, with peak spawning activity occurring between January and March. Fifty per cent of females reached first maturity at 72·1 cm L _F. At 103 cm L _F, 50% of sampled females had changed into males. Gag can be considered a monandric species, and sexual transition for this grouper seemed to occur in fish distributed within a narrow size range (85–111 cm L _F). The results are compared with those of other authors for gag stocks from the south‐east Atlantic coast of the U.S.A. and the north‐east Gulf of Mexico.     

Geographical differentiation of Aphanius dispar (Teleostei: Cyprinodontidae) from Southern Iran

The Arabian cyprinodontid Aphanius dispar (Rüppell, 1829) is known to show considerable morphological variation. It has remained unknown, however, whether this variation is a result of environmental differences or allopatric divergence owing to geographical isolation. In this study, 11 populations of A. dispar from three geographically separated basins were analysed, that is, the Makran Basin (I, one river system), the Hormuzgan Basin (II, five rivers and three hot springs) and the Helleh Basin (III, two hot springs) in southern Iran. Statistical analyses do not indicate significant differences between the fishes from river and hot spring habitats (T‐test, p < 0.05), which is also supported by the Canonical Discriminant Analysis (CDA). Nevertheless, morphometric and meristic characters of the fishes, as well as otolith morphology and morphometry, demonstrate that six phenotypic characters discriminate the A. dispar populations of the three basins, that is, (1) predorsal distance (Prdd.SL), (2) head length (HL.SL), (3) pelvic fin length (Lplf.SL), (4) number of pelvic fin rays, as well as relative length of both the (5) medial part and (6) rostrum of the otolith. In addition, these characters display a consistent pattern of variation, thus providing support for the assumption that the phenotypically different A. dispar populations are a result of geographical isolation and not related to environmental differences. It is likely that the geological history of the drainage systems caused isolation event(s) that may date back to the Pleistocene (1.8 million years before present). The high phenotypic differences might suggest that the A. dispar populations from the three studied basins represent separate subspecies or even species.     

Reproductive biology of the genusDamasonium (Alismataceae)

The reproductive biology of the genusDamasonium was studied in cultivation and in nature. A correlation was shown between flowering time and latitude. All species are self-compatible but the N. American member of the genus (D. californicum) is strongly protandrous and probably experiences high levels of outcrossing in nature. In the European taxa the stamens and the stigmas mature simultaneously but the levels of inbreeding appear to be greater in the southern species (D. bourgeai, D. polyspermum) than in the northern (tetraploid) speciesD. alisma. The Australian memberD. minus resembles the southern European species in being strongly autogamous and bud-pollination was shown to occur. Floral morphology, stigma exertion, pollen/ovule (P/O) ratio and seed weight each show a strong correlation with the degree of autogamy. Vegetative reproduction occurs only inD. californicum andD. alisma through the production of corm-buds. This study suggests that autogamy inDamasonium is accompanied by a shift in resource allocation from male (pollen) toward female (seed) function. However, further studies are required to assess the quality of seeds and their survivorship in nature.     

Reproductive biology of the Andean-disjunct genusRetanilla (Rhamnaceae)

Various aspects of the reproductive biology of the Andean-disjunct genusRetanilla (DC.) Brongn. were studied in populations ofR. trinervia andR. ephedra located in central Chile and ofR. patagonica in southern Argentina. Flowering extends from -austral- winter (early spring inR. patagonica) to early summer. The small, white, entomophilous flowers are incompletely protandrous and last four to five days. A weak pleasant odor along with nectar and pollen attract thirty-seven diurnal insect species, ten of which are probable pollinators: these include the honey bee, eight species of solitary bees pertaining toAnthophoridae (1 sp.),Colletidae (3 spp.) andHalictidae (4 spp.), and a nemestrinid fly. Although flower morphology and individual flower phenology do not fully prevent self-pollination (and geitonogamy can easily take place), the level of autogamy is low. Therefore, some self-incompatibility mechanism seems operative inRetanilla. Fruit set of open-pollinated flowers is extremely low, with a maximal value of c. 3% inR. patagonica. In this species, ripe fruits contain on average 1.37 viable seeds. Predispersal (maternal) reproductive success (percent ovules becoming viable seeds) is 2.3%. For medium to full-sized individuals this corresponds to c. 4600 potential offspring per year. As presently known,Retanilla is a reproductively uniform group, in which the Andean disjunction seems to have exerted no particular impact, which is consistent with the view that pollination generalization exerts some stabilizing influence on floral morphology and other reproductive traits.Retanilla expresses a basic rhamnacean set of traits (including protandry and self-incompatibility) showing also high pollen production and secondary pollen presentation. The latter two traits seem characteristic of theRetanilla-Trevoa clade, suggesting that a trend to increased male effort and, perhaps, dependence upon polleneating has evolved within the tribe Colletieae.     

Reproductive biology of the melon cactus, Melocactus curvispinus (Cactaceae)

We examined the reproductive biology of Melocactus curvispinus Pfeiffer (Cereeae, Cactoideae) in xeric areas of northern Venezuela. Floral traits correspond to a classic hummingbird-pollination syndrome; however, pollination is shared between hummingbirds, Leucippus fallax (Bourcier 1843), and anthophorid bees, Ceratina sp. Reproduction occurs during most of the year. Anthesis and nectar secretion occur between noon and sunset. Average daily nectar production per flower was 163.1 l, nectar sugar concentration between 29.1 and 30.2% (w/w). Hummingbirds promoted inter-plant pollen movement and were relatively more reliable floral visitors than anthophorid bees, but these insects had a higher frequency of floral visits (28.75/day) than hummingbirds (4.96/day). M. curvispinus is self-compatible and autogamous. By combining extended reproductive activity, frequent animal-mediated pollination, and selfing capabilities, this cactus possesses a mating strategy that guarantees reproduction under variable environmental conditions. We argue that based on its reproductive biology, M. curvispinus should be considered an example of evolutionary transition towards selfing within tribe Cereeae.     

Early otolith development in the critically endangered tooth-carp, <Emphasis Type="Italic">Aphanius farsicus</Emphasis> (Teleostei: Cyprinodontidae)

Otolith morphology in the tooth-carp/killifish genus Aphanius is a source of informative taxonomic characters at both the species and population level. Most work on otoliths has focused on adult specimens, while evidence of ontogenetic variation is rarely provided. In this study we describe the development of otolith morphology during the early life stages of an endangered and endemic species, the Fars tooth-carp Aphanius farsicus from southern Iran. The study material comprises 34 larvae and early juveniles representing nine different developmental stages (0–120 days post hatching), all reared under the same laboratory conditions. The results reveal (i) a significant correlation between standard length and otolith size (length) in larval and early juvenile stages, (ii) clear differences in otolith morphology between larvae/early juveniles and adults, and (iii) a temporal link between the appearance of the sulcus on the otolith’s inner face and the emergence of the dorsal and anal fins. Our results indicate that otoliths of Aphanius can be recognized as originating from larval or early juvenile fish based on their short rostrum and antirostrum lengths and wide excisura, in addition to their small size. These immature otoliths are, however, not diagnostic at the species level in A. farsicus, nor most probably in other species of tooth-carp. The outcome of our study is also of interest to palaeontologists working with fossil killifish otoliths, as it can help avoid misinterpretation of ancient species diversity.     

Life-history variations of killifish (Aphanius sophiae) populations in two environmentally different habitats in central Iran

Two populations of Aphanius sophiae from two different habitats (one in a spring with stable environmental conditions and the other in a river with variable conditions) were examined to determine whether these conditions elicit differences in life history traits. Age composition revealed that females from the spring live longer. Von Bertalanffy growth parameters showed that L(∞) in the river population was higher than in the spring population. GSI showed a shorter reproduction period in A. sophiae from the river system. Egg diameter was significantly larger in the spring population. These results confirm the hypothesis of the response of killifish to local selective pressures in different habitats through adaptations via changes in the duration of the reproductive period, egg diameter, size changes, age composition and growth rate.