BMC Zoology最新文献

Background: Paphia undulata, The Short-Necked Clam, is an edible marine bivalve that is consumed internationally and locally in Egypt. Overfishing and pollution have caused population declines in Egyptian fisheries during the last decade. Accurate reproductive biology knowledge is critical for designing long-term exploitation strategy for this resource. P. undulata spawning and gametogenic cycle research were carried out from January to December 2020 along Timsah Lake, Suez Canal, Egypt.

Results: These clams are functionally dioecious with a very low incidence of hermaphroditism. The sex ratio of the clam population was 1.0:1.07:0.04 for male, female and hermaphrodite respectively. The shell lengths of the collected clams were 4.64 ± 0.83 cm in males, 4.55 ± 0.9 cm in females and 4.19 ± 0.3 cm in hermaphrodite clams. The sizes at the onset of sexual maturity in both males and females were 2.1 cm and 2.5 cm respectively.

Conclusions: Reproductive studies revealed that this species has a prolonged spawning season that is not restricted to a specific period.

Background: Ecomorphological studies of lizards have increasingly employed comparison of claw morphology among species in relation to spatial niche use. Typically, such studies focus on digit IV of the autopodia, especially the pes. Uniformity of claw morphology among digits is more often implicitly assumed than tested.

Results: Using four species of Cyrtodactylus, comprising two generalist and two scansorial taxa that use different substrates, we examined whether claw morphology is uniform among digits and among species. We found that, within each species, ventral claw curvature is uniform across all digits whereas there are small but insignificant differences in ventral claw length and claw depth. The claws of the pes of each species are longer and deeper than those of the corresponding digits of the manus. The claw of digit I of each species is significantly shorter and shallower on both autopodia compared to those on digits IV and V (digit I, including its claw, is idiosyncratically variable among lizards in general).

Conclusions: We conclude that digit IV is an adequate representative of claw form in each species and exhibits variation among species, thereby serving as an exemplar for use in studies of potential discrimination between ecomorphological types in studies of Cyrtodactylus.

Background: Most aquatic biota's reproductive biology and life cycle are essential to the sustainable management and development of coastal ecosystems and aquaculture. The bivalve Paphia textile (Gmelin 1791), also known as Paratapes textilis, has an economic value in Indo-Pacific waters, including the Red Sea and the Suez Canal lakes, the Egyptian coasts. However, P. textile suffers from extensive fishing and exploitation.

Aim: The present work aims to study the Paphia textile's reproductive cycle on the Egyptian coasts of the Red Sea for the first time. It helps to manage and develop the coastal ecosystems and aquaculture.

Methodology: Samples were collected monthly from two saline lakes in the Suez Gulf from December 2019 to November 2020. As part of the comprehensive research study, sex ratio, condition index, sexuality, histological analysis of gonads, shell size, and gonad index were used to investigate the reproductive cycle.

Results: The results reveal a male-biased sex ratio, possibly due to anthropogenic stressors. The Paphia textile is dioecious. No hermaphrodite cases were observed in the studied specimens. The condition index in winter and spring indicates periods dominated by mature individuals. Five reproductive maturity stages were assigned for both P. textile males and females. Due to the simultaneous development of several developmental stages monthly throughout the sampling year, warm water may be responsible for non-sequential gametogenic cycles. As measured environmental parameters correlate with maturity stages, temperature, salinity, and chlorophyll a play important role in gonad growth. The size at first sexual maturity at which 50% of the Paphia textile population reached maturity ranged from 28.60 to 31.50 mm for females, and between 31.70 and 34.10 mm for males. As the gonad index increases during the ripe stages, this index decreases during the resting, spawning, and spent phases.

Conclusions: The findings suggest the most suitable temperature for aquaculture spawning is between 20 °C and 30 °C in subtropical waters. Fishing should generally be prohibited at sizes less than 28.60 mm for better management and sustainability of this valuable aquatic resource on the Egyptian coasts of the Red Sea.

Background: Under the family Tephritidae, Bactrocera zonata (Saunders) is a serious pest, attacking fruits and vegetables causing large quantitative and qualitative damages throughout the world. Fruit flies require proteinaceous food for sexual maturation and egg development. Therefore, food bait attractants are frequently utilized for fruit fly detection, monitoring, mass trapping, and control. Using a Y-shape olfactometer (behavioral tests), we selected the best synthetic proteinaceous food bait attractants to volatiles identified by fruit fly antennae. The responses of B. zonata adults, male and female, to some ammonium compounds (ammonium acetate (AA), trimethylamine (TMA), and putrescine) that were mixed with certain food attractants were evaluated under laboratory conditions. Using flies ranging in age from 5 to 30 days, possible mixtures were discovered that might be useful in developing fruit fly attractants for both males and females. So, four base baits were developed by mixing protein hydrolysate with jaggery, papaya powder, kachri powder, potassium hydroxide (KOH), and guava pulp. Finally, thirty-two (32) synthetic blends were developed when the above four base baits were mixed with synthetic attractants.

Results: The olfactometer bioassay indicated that protein hydrolysate and jaggery-based baits were effective in attracting both male and female flies throughout their adult lives when combined with AA + putrescine (Bait 6) and AA + TMA + putrescine (Bait 8). Similarly, protein hydrolysate + guava pulp-based baits combined with AA + putrescine (Bait 6) and AA + TMA + putrescine (Bait 8) was effective in attracting both male and female flies from 5 to 30 days of age. The pH of all 32 synthetic blends was measured and ranged from 4.77 to 11.35.

Conclusions: According to our observation, the variation in pH may be due to differences in chemical composition between the attractants and food constituents. The pH of protein bait attractants may be an important factor in the attraction efficiency of B. zonata males and females.

Background: Dumpsites play key role in conservation of birds. A study was conducted to assess the diversity and abundance of birds in dumpsites of Afar region, Ethiopia from August, 2019 to March, 2020, covering both the wet and dry seasons. A total of nine dumpsites that contain domestic wastes found in different towns of Afar region were selected. Point count technique was employed to identify and count the birds. Shannon-Weiner diversity index was used to estimate species diversity and Two-way ANOVA was used to test birds' species richness and abundance variation across dumpsites and seasons.

Results: A total of 48 bird species consisting of one endemic and 10 globally threatened species were recorded. Red-billed Quelea, Marabou Stork and Egyptian Vulture were the most abundant species. There was a significant difference in bird species richness and abundance among dumpsites (F = 8.44, df = 8, P < 0.05) and F = 15.507, df = 8, P < 0.05), respectively. Moreover, a significant difference in abundance was also observed between the two seasons (F = 19.339, df = 1, P < 0.05). The highest species diversity (H' = 3.18) was observed during wet season in Abala and Afambo dumpsites and the highest species evenness (E = 0.86) was observed during dry season in Afdera.

Conclusion: Bird species diversity and abundance among dumpsites was high, and man-made disturbance are main threats for conservation of birds in the area. Therefore, conservation measures are needed to maintain survival of birds mainly the globally threatened species. Moreover, proper management of dumpsites is vital to support the waste dependent birds.

Background: Chrysopa pallens is one of the most beneficial and effective natural predators, and is famous for its extensive distribution, wide prey spectrum, and excellent reproductive performance. This study examined the anatomy and fine structure of the C. pallens reproductive system and spermatogenesis.

Results: The male reproductive system of C. pallens comprises a pair of testes, a vas deferens, seminal vesicles, accessory glands, and short ejaculatory ducts. The testes were already mature on the day of emergence, but the accessory glands did not mature until 5 days post-emergence. In early spermatids, the flagellum had an axoneme on one side of the two mitochondrial derivatives. The nucleus was surrounded by parallel crystalline and paracrystalline materials. The spermatid envelope extends towards the paracrystalline material in a tail-shaped wing. In mature spermatids, the axoneme is located between the two accessory bodies and mitochondrial derivative sets. The parallel-crystalline and paracrystalline materials disappeared. In the testes, the wall of seminal cysts consists of a layer of epithelium, a muscular-connective sheath, and several vesicles of different sizes. The mature seminal cysts contained 128 spermatozoa. The accessory gland is composed of six parts: ventral papilla-like protuberance, anterior glandular lobe, lateral glandular lobe, seminal cyst, posterior kidney-shaped lobe, and posterior papilla-like protuberance. Muscle fibers and secretory granules are extensive.

Conclusions: This study provides information on the reproductive system of C. pallens and offers a resource for taxonomy and reproductive biology.

Background: The genus Sparasion, endoparasitoids of Tettigoniidae, occur in the Nearctic, Palearctic, Afrotropical and Oriental regions. It is absent in the Neotropics and Australasia. Of the thirteen species found in the Oriental region only a single species is from India.

Results: Two new species groups - Sparasion bilahari species group and Sparasion manavati species group - are proposed for species from the Oriental region. Thirty-six species are described and illustrated of which twenty-four are new: Sparasion albopilosellus Cameron, 1906 (Pakistan); S. bhairavi Veenakumari, sp. n. (India); S. bhupali Veenakumari, sp. n. (India); S. bihagi Veenakumari, sp. n. (India); S. bilahari Veenakumari, sp. n. (India); S. cellularis Strand, 1913 (Taiwan); S. coconcus Kozlov and Lê, 2000 (Vietnam); S. coeruleus Kieffer, 1905 (Sumatra); S. cullaris Kozlov and Lê, 2000 (Vietnam); S. darbari Veenakumari, sp. n. (India); S. deepaki Veenakumari, sp. n. (India); S. domes Kozlov and Lê, 2000 (Vietnam); S. elbakyanae Veenakumari, sp. n. (India); S. formosus Kieffer, 1910 (Taiwan); S. hindoli Veenakumari, sp. n. (India); S. kalyani Veenakumari, sp. n. (India); S. kanakangi Veenakumari, sp. n. (India); S. karivadana Veenakumari, sp. n. (India); S. lividus Johnson, Masner & Musetti, 2008 (Philippines); S. manavati Veenakumari, sp. n. (India); S. meghmalhari Veenakumari, sp. n. (India); S. micromerus Kozlov and Lê, 2000 (Vietnam); S. pahadi Veenakumari, sp. n. (India); S. philippinensis Kieffer, 1913 (Philippines); S. ratnangi Veenakumari, sp. n. (India); S. rupavati Veenakumari, sp. n. (India); S. salagami Veenakumari, sp. n. (India); S. shulini Veenakumari, sp. n. (India); S. sinensis Walker, 1852 (China); S. sivaranjini Veenakumari, sp. n. (India); S. syamalangi Veenakumari, sp. n. (India); S. todi Veenakumari, sp. n. (India); S. travancoricus Mani and Sharma, 1981 (India); S. vanaspati Veenakumari, sp. n. (India); S. visvambari Veenakumari, sp. n. (India) and S. zeelafi Veenakumari, sp. n. (India). Keys to Oriental species of Sparasion are furnished. Intrasexual colour morphs among females of Sparasion is reported. Lectotype is designated for Sparasion cellularis Strand.

Conclusions: Twenty-four new species are added to the Indian fauna of Sparasion. Previously described species of Oriental Sparasion are redescribed and illustrated. Keys are furnished for all Oriental species.

Parabramis pekinensis was treated as research object in order to investigate the correlation between morphological traits and body weight. We measured 9 morphological indexes including total length (X₁), body length (X₂), body height (X₃), head length (X₄), snout length (X₅), eye diameter (X₆), eye distance (X₇), caudal stalk length (X₈) and caudal stalk height (X₉). The principal morphological traits affecting body weight were screened out and the regression equation was established. The regression equation of Y1 (age 1 group) shape character (X) and weight (Y) was Y = - 169.183 + 32.544 × ₃ + 10.263 × ₄ + 15.655 × ₇. The regression equation of Y2 (age 2 group) shape character (X) and weight (Y) was Y = - 694.082 + 7.725 × ₁ + 72.822 × ₃ + 77.023 × ₆, the regression equation of Y3 (age 3 group) shape character (X) and weight (Y) was Y = - 1161.512 + 26.062 × ₁ + 22.319 × ₂- 107.218 × ₅ + 83.901 × ₇. Gene expression was consistent with these conclusions. TOR signaling pathway expression raised in Y1 then width increased. And GH-IGF-1 signaling pathway expression raised in Y2 then the length increased. In conclusion, the paper could prove that P. pekinensis showed a growth trend, which was increasing width first and length later. In some sense, the study not only enriched the basic biological data of P. pekinensis, but also provided waiting morphological traits for selective breeding of P. pekinensis artificial breeding in future.

Background: Dromedary camel heart morphology is a crucial research topic with clinical applications. The study aims to understand the dromedary camel anatomy, morphology, and architecture of the ventricular mass.

Results: Sagittal and transverse gross sections were compared to sagittal, transverse, and 3D render volume reconstruction computed tomography (CT) scans. The subepicardial fat, which covered the heart base, the coronary groove (sulcus coronarius), the left longitudinal interventricular groove (sulcus interventricularis paraconalis), and the right longitudinal interventricular groove (sulcus interventricularis subsinuosus), had a relatively low density with a homogeneous appearance in the 3D render volume CT. The pericardium in the color cardiac window was identified better than the black and white window (ghost). Transverse and sagittal CT scans demonstrated the internal structures of the heart, including the right atrioventricular orifice (ostium atrioventriculare dextrum), right atrioventricular orifice (ostium atrioventriculare sinistrum), and aortic orifice (ostium aortae), chordae tendineae, the cusps of the valves (cuspis valvae), and the papillary muscles (musculi papillares). The papillary muscle (musculi papillares) was presented with a more moderate density than the rest of the heart, and the cusps of the valves (cuspis valvae) had a lower density. The ventricular wall (margo ventricularis) exhibited different densities: the outer part was hyperdense, while the inner part was hypodense. The thicknesses of the ventricular mural wall and the interventricular septum (septum atrioventriculare) were highest at the midpoint of the ventricular mass, and the lowest value was present toward the apical part. The coronary groove (sulcus coronarius) circumference measured 51.14 ± 0.72 cm, and the fat in the coronary groove (sulcus coronarius) (56 ± 6.55 cm²) represented 28.7% of the total cross-sectional area.

Conclusion: The current study provided more information about ventricular mass measurements by gross and CT analysis on the heart, which provides a valuable guide for future cardiac CT investigations in camels in vivo.

Background: This is the first record of the alien shrimp Mierspenaeopsis sculptilis in Brazil. The invasion was detected within Marine Extractive Reserves based on eight specimens accidentally caught by local fishermen using trawlnets focused on fisheries of native species. These specimens were transported to the Laboratory of Applied Genetics and morphologically identified as Mierspenaeopsis sculptilis (rainbow shrimp). The taxonomic status of analyzed samples was confirmed by DNA barcoding using a 627-bp fragment of the Cytochrome C Oxidase Subunit I (COI) gene.

Results: A single haplotype was recovered from the eight specimens, being identical to a haplotype reported in India, where this species naturally occurs, and in Mozambique, where the rainbow shrimp is considered an invasive species. The present analyses indicated a putative invasive route (i.e., India-Mozambique-Brazil) mediated by shipping trade.

Conclusions: This study presents the first record of Mierspenaeopsis sculptilis in Brazil, in areas of extractive reserves on the Amazon coast. Notably exotic species can cause imbalance in the ecosystem, harming native species. In view of this, the registration of new invasions is essential as they contribute to the implementation of control plans.