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 four large riverine fishes (Cyprinidae) in a man-made lake,Orange River,South Africa

The reproductive biology ofBarbus holubi, B. kimberleyensis, Labeo capensis andL. umbratus was examined in a large reservoir on the Orange River, South Africa. The findings are integrated into the existing knowledge on largeBarbus andLabeo species, which coexist in most river systems in Africa and Asia.LargeBarbus spawn on gravel beds within the river channel during floods in spring or summer. In continuously flowing regulated rivers, time of spawning is governed by water temperatures. They have moderate fecundity; large eggs, incubation time of several days and the larvae are initially immobile with large yolk sacs. In the impoundment, they spawn in the inflowing regulated river withB. kimberleyensis spawning four to six weeks later than the more cold-tolerantB. holubi, the dominant largeBarbus. Survival is generally good and the juveniles disperse throughout the lake, but unseasonal release of cold water from an upstream impoundment may cause poor reproductive success.In contrast,Labeo species generally spawn on newly flooded ground, usually leaving the main river channel. Spawning may or may not be preceded by a longitudinal migration. Labeos are relatively fecund with small (30%Barbus size) eggs which hatch quickly and the larvae swim in bursts up into the water column before sinking down again.L. capensis does not require a longitudinal spawning migration and breeds throughout the lake, depending on local conditions. Large temporal variation in gonadal development within the population can result in more than one spawning. Dispersal within the lake is poor.L. umbratus uses larger inflowing tributaries for spawning thanL. capensis and its juveniles have a much greater power of dispersal. Early dependence on external feeding and undependable occurrence of conditions for spawning and juvenile feeding makes for variable reproductive success.     

Features of reproductive biology in females of bitterlings (Cyprinidae: Acheilognathinae) from the Amur River basin

Data on morphological and functional characteristics of the ovipositor, conical organ, and ovaries in four species of bitterlings (Russian bitterling Acanthorodeus asmussii, Khanka spiny bitterling A. chankaensis, bitterling Rhodeus sericeus, and Amur bitterling R. amurensis) from the Amur River basin are obtained and reviewed for the first time. In all studied fish species, several generations of sex cells develop at the same time, which leads to releasing of oocytes in batches. The specificity of Amur bitterling, bitterling, and Russian bitterling to selection of mollusks for egg deposition is determined.     

Pethia sanjaymoluri,a new species of barb (Teleostei: Cyprinidae) from the northern Western Ghats,India

Pethia sanjaymoluri, a new cyprinid, is described from the Pavana and Nira tributaries of Bhima River, Krishna drainage, Maharashtra, India. It can be distinguished from congeners by a combination of characteristics that includes an incomplete lateral line, absence of barbels, upper lip thick and fleshy, 23–25 lateral series scales, 7–12 lateral‐line pored scales, 10 predorsal scales, 11–14 prepelvic scales, 17–20 pre‐anal scales, 4½ scales between dorsal‐fin origin and lateral line, four scales between lateral line and pelvic‐fin origin, 8–15 pairs of serrae on distal half of dorsal‐fin spine, 12–14 branched pectoral‐fin rays, 4 + 26 total vertebrae, 4 + 5 predorsal vertebrae, 4 + 13 abdominal vertebrae, 13 caudal vertebrae and a unique colour pattern comprising a humeral spot positioned below the lateral line and encompassing the third and fourth lateral‐line scales and one scale below, one caudal spot on 17th–21st lateral‐line scales with a yellow hue on its anterior side and apical half of dorsal fin studded with melanophores making the fin tip appear black. Genetic analysis based on the mitochondrial cytochrome b gene sequence suggests that the species is distinct from other known species of Pethia for which data are available.     

BarredDanio species from the Irrawaddy River drainage (Teleostei, Cyprinidae)

The three barredDanio species known from the Irrawaddy River drainage are redescribed. Two species are known from southwestern Yunnan:Danio interruptus in the Husa He and Longchuan, Jian watersheds, andD. apogon abundantly in the main river and tributaries of the Daying Jiang basin. The third species,D. shanensis, occurs in the Myitnge basin of northern Shan State, Myanmar.Danio interruptus differs from other barredDanio species by having a short, incomplete lateral line, a deeper head, and shorter thicker dark vertical bars or blotches anteriorly on the sides.Danio shanensis has the lateral line either complete or incomplete, lesser head depth, and a series of deeper narrower vertical bars.Danio apogon has no lateral line, narrow or indistinct dark vertical bars, and a wide, but indistinct, horizonatal P stripe.Danio choprae, previously considered, as a barredDanio species, is more closely related to theD. dangila species group.     

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.     

Karyotype of the cyprinid fish Alburnoides bipunctatus (Cyprinidae) from the Tigris River

Chromosome numbers and karyotypes of Cyprinid fish Alburnoides bipunctatus (Bloch, 1,782) from the River Tigris were determined by the chromosome preparation technique from uncultured kidney cells. The diploid chromosome number 2n=50, was composed of 8 pairs of metacentric, 11 pairs of submetacentric and 6 pairs of subtelo-acrocentric chromosomes (NF=88). Sex chromosomes were not determined in the this species. The results were briefly discussed with other, previously conducted studies.     

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 ofAsphodelus aestivus (Asphodelaceae)

InAsphodelus aestivus the large number of showy flowers opened per inflorescence, high nectar and pollen production, and absence of automatic self-pollination, so that insect visitation is necessary for pollination, indicate that cross-fertilization is favoured. LargeHymenoptera are the main pollinators. Hand self-pollinations result in some degree of fruit-set, but cross-pollination also yield low fruit- and seed-set. The perennial habit and polyploid status are in agreement with the breeding system of this species, with sexual reproduction being rather inefficient and active vegetative propagation.     

Reproductive biology ofPolyalthia littoralis (Annonaceae)

Flowering phenology of some annonaceous trees and reproductive biology ofPolyalthia littoralis (Annonaceae) were studied. The trees showed various types of flowering phenology within the family. Among them,P. littoralis had hermaphroditic and protogynous flowers, and exhibited continuous flowering throughout the year. Bagged flowers set fruits and seeds comparable to the control. The observations of meiotic stages and the results of castrated tests indicated no possibility of apomictic reproduction. The abscised anthers attached to torus by the extended spiral thickenings, and accomplished self-pollination. Outbreeding possibly occurs, but the following self-pollination guarantees seed set.     

Reproductive biology ofCistus ladanifer (Cistaceae)

The phenology, major floral characteristics, fruiting levels, and breeding system ofCistus ladanifer L. (Cistaceae), a common western Mediterranean shrub species, were studied in a southern Spanish population. The white, large (64 mm in diameter) flowers of this shrub appear during spring (March–May) and produce abundant pollen and nectar. In the year of study, flowers lasted up to three days, during which they were visited by a diverse array of insects including beetles, flies, and bees. Hand-pollinations revealed that flowers do not set any seed unless cross pollen is applied to the stigma. Microscopical observations indicate that self pollen tubes grow down the stigma but invariably fail to induce fruit maturation. At the plant level, all estimates of fecundity investigated (number of seeds per capsule, proportion of ovules developing into seed, and proportion of flowers setting fruit) were highly dependent on nearest neighbour distance, with isolated plants setting as little as 0% fruit. In contrast, plants within a clump often transformed into fruit as much as 90% of the flowers. At the population level, seed output was estimated to range between 3,000 and 270,000 seeds per plant during 1991.     

Reproductive ecology of the striped bitterling Acheilognathus cyanostigma (Cyprinidae: Acheilognathinae)

The reproductive ecology of the striped bitterling Acheilognathus cyanostigma was investigated in a small pond in Mie Prefecture, central Honshu, Japan. A. cyanostigma was the only species of bitterling in the study pond, where only a single species of mussel Anodonta woodiana was present. Spawning of A. cyanostigma was recorded between early April and early July, peaking between late April and mid-June in 2003. Ovipositor length during the spawning period ranged from 19.2 to 42.8 mm, and was positively correlated with female body length, but did not show significant seasonal variation. The eggs are elliptical with a volume of approximately 1.5 mm³. Egg size correlates positively with female body size, and both egg shape and volume changed significantly with season. The embryos were located on host mussel gills approximately 30 mm from the exhalant siphon and were found more frequently on the inner rather than the outer mussel gills. The possible ecological significance of these observations is discussed in the context of the adaptations of A. cyanostigma for utilizing mussels for oviposition.     

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.     

Reproductive biology of Lactoris fernandeziana (Lactoridaceae)

Lactoris fernandeziana, monotypic in its family, is endemic to the cloud forests of Robinson Crusoe Island. Although there has been considerable study of the relationships of Lactoris, as a rare species and as a putative primitive paleoherb, little is known of its reproductive biology. Knowledge of the latter is essential for effective conservation programs. The species is gynomonoecious. The overall proportion of flowers is ∼1 female:1 hermaphrodite. The inconspicuous semipendulous green flowers, usually in mixed-gender inflorescences, do not produce rewards. Hermaphrodite flowers are herkogamous and protogynous. Pollen grains are shed from the extrorse anthers in permanent dry tetrads. There is a mean of 12879 tetrads per hermaphrodite flower. Both flower types bear an average of ∼18 ovules. The P/O (pollen/ovule) ratios imply facultative or obligate xenogamy, but hand pollinations show that Lactoris is self-compatible. No floral visitors were ever observed, but stigmata of open-pollinated flowers bore tetrads, and 64% of such styles had pollen tubes. Flowers enclosed in large mesh (1 mm) bags bore similar numbers of tetrads and pollen tubes. Thus, we conclude that Lactoris is anemophilous, a syndrome perhaps reflected by the P/O ratio. Low genetic diversity (isozymes and DNA) supports selfing and implies limited distance wind pollen dispersal. The small size of the island, the ± 1000 extant Lactoris plants, coupled with anemophily, self-compatibility, and pendant flower position, have yielded a geitonogamous system with high seed set and low genetic diversity. If inbreeding depression is expressed, it is in seed germination and seedling vigor, for Lactoris is very difficult to cultivate. For this species, effective conservation practices need to focus on habitat preservation and promotion of outcrossing.     

Reproductive regulation in the female Japanese minnow, Pseudorasbora parva (Cyprinidae)

The Japanese minnow, Pseudorasbora parva, is a multiple spawner that lays eggs repeatedly during the spawning season. In laboratory aquaria, 19 of 63 females did not spawn, whereas 44 other females laid 167 to 6285 eggs in 1 to 14 mating sequences. Neither fish density nor sex ratio (number of males per female) affected fecundity, but the increase in fish density significantly decreased the growth rate of females. The increase in male length significantly increased fecundity in aquaria which contained only a single male, whereas it decreased female growth rate. These relationships were not evident in aquaria housing three or ten males. Since larger males were more dominant and had larger testes than smaller males, the correlation between fecundity and male size strongly suggests that individual females regulated fecundity to increase their reproductive success.     

Reproductive biology of Butea monosperma (Fabaceae)

The reproductive biology encompassing phenology, floral biology, pollination and breeding systems, of Butea monosperma, a beautiful tree of the Indian subcontinent, was investigated in a protected dry, deciduous forest located in New Delhi. Phenological studies indicated that although the species shows a regular flowering season, all trees do not flower every year. Flowers are typically papilionaceous; the stigma is wet papillate and the style is hollow. The flowers show characteristics of bird pollination being large and bright orange-red in colour with copious amounts of nectar, and exhibiting diurnal anthesis. Although the flowers are frequented by as many as seven species of birds belonging to six families, only one species, the purple sunbird (Nectarinia asiatica), is the effective pollinator. The flowers are also pollinated by the three-striped squirrel (Funambulus tristiatus). Unlike other flower visitors, these two pollinators forage the nectar from the open side of the keel (legitimate path) during which pollen grains are deposited on their body parts. After the first visit of a sunbird or a squirrel, virgin flowers showed pollen load on the stigma and developed into fruits. B. monosperma shows a weak form of self-incompatibility. Fruit set following manual self-pollination (5.25 %) was comparable with open-pollination (approx. 5 %) but was significantly lower than manual cross-pollination (22.51 %). This indicates that there is a high degree of geitonogamous pollination in this species, which may lead to a weakening of self-incompatibility as a means of reproductive assurance. The results are analysed in the light of prevailing discussions on specialized vs. generalized pollination systems.     

A new Pseudophoxinus (Teleostei,Cyprinidae) species from Asi River Drainage (Turkey)

Pseudophoxinus turani sp. n. is described from the İncesu Spring (Hassa-Hatay) drainage of Asi River, Turkey. It is distinguished from other Eastern Mediterranean Region Pseudophoxinus species by a combination of characters: lateral line incomplete, with 12–25 (commonly 16–21) perforated scales and 38–46+2-3 scales in lateral series (commonly 41–44+2-3); 10–11 scale rows between the lateral line and dorsal-fin origin; 3–4 scale rows between the lateral line and the pelvic–fin origin; dorsal fin with 7½ branched rays; anal fin commonly with 7½ branched rays; 8-11gill rakers on the first branchial arch; dorsal profile markedly convex with marked hump at the nape, ventral profile less convex than dorsal profile; a small, irregular, black blotch on the base of the caudal fin; mouth terminal, with slightly distinct chin, its corner not reaching vertical through anterior margin of eye; snout somewhat long, with rounded tip; and its length greater than eye diameter.     

Reproductive biology of female striped dolphin (Stenella coeruleoalba) from the western Mediterranean

Data on age and length at sexual maturity, calving interval, lactation period, and ovulation and pregnancy rates were analysed from 84 female striped dolphin collected during the Mediterranean morbillivirus epizootic. Age was determined by counting growth layer groups in tooth dentine, and reproductive status was determined by the macroscopic examination of the ovaries and the uterus. Age at sexual maturity (ASM) was estimated using two different methods; giving average estimates of 12 and 12.3 years. The average length at sexual maturity was 187 cm and the calving interval was four years. The annual pregnancy rate (APR) was calculated using two different criteria. In the first, only females that were pregnant at the time of death, as evidenced by the presence of a foetus, were incorporated in the calculations. This method gave an estimate of 8.9% as the apparent pregnancy rate of the dolphins killed by the epizootic. The second method incorporated in the calculations females that were pregnant at the time of death and females that had young corpus albicans in the ovaries and a distended uterus. This method is considered to reflect the true pregnancy rate of the population and gave an estimate of 25%. Estimates of ovulation rate (0.401) and lactation period (16 months) were considered to be potentially affected by the disease and, therefore, biased. These estimates reflect a peculiar situation of the diseased dolphins but are useful for comparative purposes. Estimates of ASM and APR, parameters which are not likely to be affected by the disease, differed markedly from those of other Stenella populations and could indicate a density-dependent response, possibly reflecting food limitations.     

Length–weight relationships of Dermogenys pusilla Kuhl & van Hasselt, 1823 (Zenarchopteridae) and Labeo bata (Hamilton, 1822) (Cyprinidae) from the Ganges River (NW Bangladesh)

Length‐weight relationships (LWRs) were determined for Dermogenys pusilla (n = 75) and Labeo bata (n = 304) from the Ganges River, northwestern Bangladesh, collected between July 2013 and June 2014, using traditional fishing gear (e.g. cast net, square lift net and gill net). Total length (TL) was measured to 0.1 cm and whole body weight (BW) was taken to the nearest 0.1 g for each individual. The TL varied from 6.60 to 16.10 cm for D. pusilla and 7.90–25.20 cm for L. bata. The BW ranged from 1.20 to 10.90 g for D. pusilla and 4.70–167.30 g for L. bata. All LWRs were highly significant (P < 0.001), with all r² values ≥0.976. Moreover, the present study provides a new record of the maximum length (16.10 cm TL) for the D. pusilla female. The present study can assist in the management of these two endangered species in the Ganges River ecosystem.