Females In Total Length Research Articles

Cortical bone maintenance and loss in Colonial Mexico City: Analysis of sex‐ and age‐related differences

AbstractPrevious research has demonstrated significant age‐ and sex‐related differences in bone loss in European populations. This study utilizes metacarpal radiogrammetry to analyze cortical bone thickness and bone loss for a sample of indigenous individuals (n = 120) from the Hospital Real San José de los Naturales (HSJN) skeletal collection in Colonial Mexico City. The results indicate statistically significant differences between males and females in total length, total width, and cortical thickness, but no difference in the standardized cortical index measure. There are significant differences in age groups for all measures except total length and the population follows a similar pattern of decreased cortical index over the life course. When age and sex are considered together, females begin this bone loss from young to middle adulthood with continued loss in old adulthood; however, males do not see a decrease in cortical index until old adulthood. While these results are consistent with previously reported patterns of bone loss, the HSJN population has higher levels of peak cortical bone in young adulthood than any archeological European populations. We suggest that this increased peak bone mass may reflect differences in diet that include higher levels of calcium and magnesium as a result of the traditional practice of softening corn by boiling it in limewater (nixtamalization). Similarly, a small sample of African descendant individuals (n = 5) from the HSJN population was compared with the averages for indigenous individuals in the collection and indicated a variation in bone size, though predominantly higher levels of cortical index that may also suggest important population differences that should be further explored. This research provides important comparative data on bone maintenance and loss that supports previous hypotheses that a higher nutrient diet in modern populations may be the key factor in increased peak bone mass compared with archeological populations.

EVALUATION OF FEEDING INDICES TO ANALYSE THE FOOD PREFERENCE AND FEEDING RATE OF MACROBRACHIUM ASSAMENSE PENINSULARE (TIWARI, 1958) FROM RAWASAN STREAM OF GARHWAL, CENTRAL HIMALAYA, INDIA

In this paper the feeding index (FI), Gastro somatic index (GaSI) and Food Prevalence Index (FPI) of freshwater prawn Macrobrachium assamense peninsulare were evaluated to assess the quantity and quality of food preferred by it in the Rawasan stream. A total of 401 prawns were collected during a span of two years from five selected sites in the Rawasan stream of Garhwal in Central Himalaya, India from August 2013 to July 2015. Collected prawns were in the size range of 20-75 mm in males and 24-65 mm in females in total length. The stomach contents of 10 collected specimens were examined monthly and observed that 35% of the stomach was full or semifull and 15% stomach were empty. The highest Gastro somatic value was obtained 2.95±0.80 during June in the male and 3.25±0.44 during May in the female. After that, it gradually decreased in both the sexes and is repeated in cyclic patterns each year. More or less a similar trend was reported in the feeding index value during the study which indicates a significant relationship between feeding intensity and Gastro somatic index. The highest Food Prevalence Index (FPI) was seen as fragments of animal matter in both sexes, which was (88.48) in male and (58.26) in female prawns and the lowest FPI value was sand and debris (7.9 and 5.7) in male and female prawn respectively. The main food items were the fragment of plants as well as animals, diatoms, algae, and sand. Overall, the results show that this prawn is selectively abstemious.

Morphological characterization of pirarucu Arapaima gigas (Schinz, 1822) gonadal differentiation.

Arapaima gigas is a giant air-breathing and bony tongue fish from the Amazon basin and a promising species for aquaculture. A. gigas farming industry is still not established because of the lack of information on its reproductive physiology. Reproduction in captivity cannot be manipulated or stimulated, and the identification of males and females in a broodstock is not easy. We aimed to reveal the morphological sex differentiation of pirarucu as studies involving gonad development are essential to understanding the reproductive physiology of any species. We performed histological analysis on the whole body and extracted the gonads of 150 juveniles. The first sign of ovary differentiation is the sex-specific rearrangement of the germ cells. In 9 cm total length females, the germ cells group into nests and are restricted to the lateral face of the gonad, in close contact with the abdomen wall. With further development, this region invaginates and that later develops into ovigerous lamellae. Meiosis starts soon after ovary differentiation. In males, the germ cells are scattered along the elongated differentiating testis at first, and later become more restricted to the central region where the spermatogonial cysts start to develop. Somatic and germ cells are jointly involved in the cellular reorganization during gonadal differentiation, specifically when the germ cells begin to establish new associations during the development of both the germinal epithelium and stroma. RESEARCH HIGHLIGHTS: In Arapaima gigas, the ovary differentiation occurs in 9 cm TL females and it is marked by the rearrangement of germ and somatic cells; and the germ cells entering meiosis with no formation of ovarian cavity; testis differentiation occurs later and meiosis does not start in males smaller than 80 cm TL.

Pola Pertumbuhan Ikan Peam (Leptobarbus melanopterus) di Taman Nasional Danau Sentarum Kabupaten Kapuas Hulu

Overfishing has been being the major problem for Leptobarbus melanopterus population in Danau Sentarum National Park. This activity was feared could affect the declining of L. melanopterus population in the future. This research aims to determine growth pattern of L. melanopterus through length-weight relationship and relative weight analysis. The total of 64 fishes were collected which consisted of 32 males and 32 females. The range of male total length was 146-248 mm with weight was 40-170 gram, whereas total length female was ranging 141-299 mm with weight was 40-350 gram. Based on the regression analysis of length-weight data, the b value of male and female were estimated 2,46 and 2,81 respectively. Moreover, the b value of all samples without distinguishing sex type was 2,69 with relative weight was 101,33. The results of this research confirms that either females or males has negative allometric growth pattern.

Some biological characteristics of Sefidrud loach, Oxynoemacheilus bergianus (Teleostei: Nemacheilidae), in Aras River, northwestern Caspian Sea basin

Some 190 specimens of Sefidrud loach, Oxynoemacheilus bergianus , were collected from Aras River (Northwestern Iran) and age, size, and some biological characteristics of the samples were investigated from March to July 2013. The maximum age was 3 + years. The specimens ranged in size from 42 to 64mm for males and 45 to 61mm for females in total length, weighing from 0.62 to 2.03g for males and 0.63 to 1.66g for females. Length-weight relationship was estimated as W= 0.00005TL 2.81 for females, W= 0.000005TL 3.11 for males and W= 0.000008TL 2.97 for the sexes combined. Sex ratio was 1M:0.9F, in favor of males (P<0.05). The growth model was isometric for males, females and sexes combined. The calculated maximum Fulton’s condition factor ( K F ) and allometric condition factor ( K A ) were 0.900 and 0.010 in males and 1.000 and 0.009 in females, respectively. The most frequent age classes in the samples were 2 + years for both males and females. In general, as most other loaches, Sefidrud loach is also a small short lived species with a low frequency in Aras River.

Gonadal State and Condition Factor of Oreochromis Niloticus (Linnaeus 1758)in a Hypereutrophic Lake

Condition factor, sexual maturity and length-weight relationship of 1132 Oreochromis niloticusinhabiting the hypereutrophic Lake Chivero in Zimbabwe were studied. Fish samples were collected through gill netting and from selected commercialfisheries around the lake from February - November 2011. Comparative analysis of age and size at maturity revealed that the O. niloticus reached maturity at 30±2.5 mm males and 50±3.6 mm females in total length. There was a significant difference in sexual maturity in both sexes with the inactive (I) stage more frequent. Both sexes of fish indicated a negative allometric increase in weight.August and November were determined as the most intensive and sensitive breeding periods for O. niloticus in Lake Chivero.Fishing activities in the lake need to be regulated in tandem with the breeding cycles of the O. niloticus.

Description of a new species of skate of the genus Malacoraja Stehmann, 1970: the first species from the southwestern Atlantic Ocean, with notes on generic monophyly and composition (Chondrichthyes: Rajidae)

The first report of a western South Atlantic soft skate, genus Malacoraja Stehmann, 1970, is described as Malacoraja obscura, new species, from the southeastern Brazilian continental slope off the states of Espírito Santo and Rio de Janeiro, in depths ranging from 808-1105 m. The new species is known from five specimens and is distinguished from congeners by its unique dorsal coloration with small, faded white spots on disc and pelvic fins, by retaining in larger specimens an irregular row of thorns along dorsal midline of tail (extending from tail base to two-thirds of tail length in 680 mm total length female), and by presenting a ventral tail midline devoid of small denticles only at base (naked region not extending posterior to pelvic fin rear margin). Further diagnostic characters in combination include the lack of scapular thorns in larger specimens, elevated number of tooth rows (64/62 tooth rows in subadult male of 505 mm TL, and 76/74 in large female of 680 mm TL) and vertebrae (27-28 Vtr, 68-75 Vprd), ventral disc and tail with a uniform dark brown coloration, paired postventral fenestrae on scapulocoracoid, enlarged posterior postventral fenestra, circular foramen magnum and paired internal carotid foramina on braincase floor. Adult males were unavailable for study, but an anatomical description of M. obscura, n. sp., is provided. Comparisons are made with all known material of M. kreffti, literature accounts of M. senta, and with abundant material of South African M. spinacidermis; M. obscura, n. sp., most closely resembles M. spinacidermis from the eastern South Atlantic in squamation, coloration and size. Malacoraja is monophyletic due to its unique squamation and rostral appendices, and apparently comprises two species-groups, one for M. obscura and M. spinacidermis, and the other for M. kreffti and M. senta, but clarification of species-level relationships must await more anatomical information, particularly of the latter two species.

Growth of the human metatarsal bones in the fetal period (13-24 weeks postconception): a quantitative study.

We studied metatarsal growth in 600 metatarsal bones (60 pairs of feet) taken from 60 human fetuses (35 males and 25 females) ranging in age from 13 to 24 weeks postconception. The data obtained for the total length (TL) and for the ossified metatarsal length (OML) were correlated to fetal crown-rump length (C-R). The ossified metatarsal length presented a growth rate greater than the total length growth rate. There was no statistical difference between either the right and left metatarsals or males and females in total length and ossified metatarsal length growth during the period studied. We believe that metatarsal growth curves could be used to monitor fetal foot growth.

Spawning and fecundity of the western king prawn, Penaeus latisulcatus Kishinouye, in Western Australian Waters

The microscopic and macroscopic changes which occur during ovary development to spawning have been investigated for P. larisulcatus. The latter stages (3 and 4) of development and the act of spawning have been found to be confined to single intermoult periods, with spawning being possible during each of a series of consecutive intermoult periods. Fecundity was found to vary significantly with the size of the individual, with the number of eggs ranging from approximately 105000 (123 mm total length female) to 650000 (217 mm total length female) at each spawning. The use of an index of population fecundity in combination with estimates of spawning frequency to document spawning seasons is discussed. Using the population fecundity method the two northern populations have been shown to have a year round spawning season, with maximum spawning occurring from autumn to spring. while the southern population was shown to have shorter seasons over summer. A relationship between ovary development and temperatures in excess of 17�C is suggested as the probable cause of the differences in duration of spawning seasons along the Western Australian coastline.