scholarly journals Spatial and temporal length distribution of Zungaro zungaro caught in the Orinoco River Basin of Colombia

2016 ◽  
pp. 5211-5221
Author(s):  
Hernando Ramírez-Gil
Keyword(s):  
River Basin ◽  
Sexual Maturity ◽  
Length Distribution ◽  
Historical Records ◽  
Male And Female ◽  
Orinoco River ◽  
Size At Sexual Maturity ◽  
Males And Females ◽  
Average Size ◽  
River Drainages

ABSTRACT Objetive. To determine the effect of fishing on capture size of both male and female Zungaro zungaro catfish, historical records of size and spatial distribution of the species were analyzed from the Orinoco Basin in Colombian. Materials and methods. Information was collected by sampling fishing port landings in the region between 1979 and 2011. Each specimen was measured, weighed and sexed. With 5411 records, the average size at capture were compared in time and among the different ports. Size at 50% maturity was estimated by quinquennium. Results. The average commercial capture sizes of Z. zungaro ranged from 35 to 161 cm standard length, with differences between males and females. From 1979 to 2011, in Puerto Lopez, the size at sexual maturity decreased from 123.8 to 83.4 cm in females and from 93.3 to 61 in males. In the annual cycle the greater average capture size in females was from April to July and for males from May to June. Average annual length is higher in the higher parts of the Meta and Guaviare river drainages. In the last quinquennium the size at 50% maturity had fallen 10 cm in females and 5 cm in males and it is higher than the average capture size. Conclusions. Populations of Z. zungaro in the Colombian Orinoco River Basin have been affected by overfishing and selective fishing of females. RESUMEN Objetivo. Determinar el grado de afección en la población de Zungaro zungaro a partir del análisis del comportamiento histórico y espacial de las tallas de captura de hembras y machos de la especie en la Orinoquia colombiana. Materiales y métodos. La información fue colectada mediante muestreos a los desembarcos en puertos pesqueros de la región entre 1979 y 2011. Cada ejemplar fue medido, pesado y sexado. Con 5411 registros, se estableció la distribución de las tallas medias de captura, que se compararon en el tiempo y entre los diferentes puertos. Se estimó la talla de madurez gonadal (TMG) por quinquenios. Resultados. El rango de las tallas de captura comercial Z. zungaro fue de 35 a 161 cm longitud estándar (LS), con diferencia entre machos y hembras. Entre los años 1979 a 2011, en Puerto López, la talla promedio de captura anual (LS) disminuyó de 123.8 a 83.4 cm en hembras y de 93.3 a 61 cm en machos. En el ciclo anual la mayor talla promedio de captura de hembras se presenta en abril a julio y de machos en mayo y junio. La talla promedio de captura anual (TPCA) es superior en las partes altas de los ríos Meta y Guaviare. En el último quinquenio la TMG ha disminuido 10 cm en las hembras y cinco cm en los machos y es superior a la TPCA. Conclusiones. Hay afectación sobre la población explotada de Z. zungaro por sobrepesca por crecimiento y pesca selectiva de hembras en la Orinoquia colombiana.

Changes in female lobster (Homarus americanus) size at maturity and implications for the lobster resource in Long Island Sound, Connecticut

2001 ◽  
Vol 52 (8) ◽  
pp. 1283 ◽  
Author(s):  
Donald F. Landers Jr ◽  
Milan Keser ◽  
Saul B. Saila
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Long Island ◽  
Homarus Americanus ◽  
Long Island Sound ◽  
Female Size ◽  
Size At Maturity ◽  
Size At Sexual Maturity ◽  
Average Size ◽  
Island Sound

Population theory predicts that, under conditions of high age/size-specific mortality rates, individuals in highly exploited populations increase their fitness by decreasing size at sexual maturity, relative to less exploited populations. The benefit of early reproductive maturation is that individuals have a higher probability of surviving to maturity and contributing progeny to maintain the population. Empirical evidence, based on morphometric data from nearly 60 000 female lobsters collected since 1981, suggests that size at sexual maturity of female lobsters in Long Island Sound (USA) has recently decreased. Our findings were supported by decreases in average size and increases in abundance of egg-bearing females over the past two decades. Changes in female size at maturity and subsequent higher egg production may also help to explain the recent increase in lobster recruitment and landings. It is unclear whether these changes were caused by density-dependent factors related to the high exploitation of the species, by natural environmental factors (e.g. higher seawater temperatures), or a combination of the two.

scholarly journals Life-history strategies associated to reproduction of three Hyphessobrycon species (Characidae) in lentic environments of upper Paraná River basin

2013 ◽  
Vol 25 (4) ◽  
pp. 398-405 ◽  
Author(s):  
Cristina da Silva Gonçalves ◽  
Ursulla Pereira Souza ◽  
Fabio Cop Ferreira ◽  
Alexandre Peressin ◽  
Francisco Manoel de Souza Braga
Keyword(s):  
Life History ◽  
River Basin ◽  
Sexual Maturity ◽  
Life History Strategies ◽  
Oxbow Lakes ◽  
Parana River ◽  
Three Samples ◽  
Size At Sexual Maturity ◽  
Upper Paraná River ◽  
Upper Paraná River Basin

AIM: Life-history strategies in fish include essential parameters related to offspring survivorship, fecundity and time of reproduction, which represent adaptive traits that enable a species to deal with spatial and temporal variability of abiotic conditions. This study aimed to compare reproductive traits associated to life-history theory for three Hyphessobrycon species from two lentic environments (four natural oxbow lakes and a man-made reservoir) of Mogi Guaçu River, upper Paraná River basin. METHODS: Specimens were collected with four minnow traps between August 2005 and July 2006 to cover dry and wet seasons (three samples in each season, and three samples in each environment). RESULTS: Reproductive strategy of H. bifasciatus and H. eques, which predominated in the oxbow lakes, differed from H. anisitsi in the reservoir. Hyphessobrycon bifasciatus and H. eques were single spawners with lower fecundity and size at sexual maturity, but invested more in number of eggs per body gram, while H. anisitsi was a multiple spawner species with higher fecundity, larger size at sexual maturity and body size. CONCLUSIONS: In seasonal environments, single spawners are synchronized with the floods to maximize juvenile survivorship, while reservoirs harbors multiple spawners’ fish due to the reduced fluctuation between high and low floods resulting from dam operation. Therefore, the seasonal condition in the oxbow lakes due to the flood pulse favored single spawners’ tactic, as showed by H. bifasciatus and H. eques. In contrast, the multiple spawning of H. anisitsi seems to be related to the more stable environmental condition throughout the year provided by the dam. Life-histories reported herein to Hyphessobrycon species must be common to other characid fishes inhabiting similar environments.

scholarly journals HEMIBRYCON GUEJARENSIS, A NEW SPECIES FROM THE GÜEJAR RIVER, ORINOCO BASIN, COLOMBIA (CHARACIFORMES: CHARACIDAE) WITH A REVIEW THE POPULATIONS IDENTIFIED AS HEMIBRYCON METAE

2017 ◽  
Vol 29 (1) ◽  
pp. 38-52 ◽  
Author(s):  
César Román-Valencia ◽  
Raquel I Ruiz-C ◽  
Donald C. Taphorn B.
Keyword(s):  
New Species ◽  
River Basin ◽  
Careful Analysis ◽  
Mountain Range ◽  
Pectoral Fin ◽  
Orinoco River ◽  
Allopatric Species ◽  
River Drainages ◽  
Caribbean Populations ◽  
Pelvic Fin

Hemibrycon guejarensis, new species, is described from the Güejar River, La Macarena mountain range, upper Guaviare River drainage, Colombia. The new species is distinguished from most cis-Andean congeners (H. jabonero Lake Maracaibo and adjacent Caribbean drainages, H. metae which is found in the Guavio River, some Orinoco and Caribbean River drainages in Venezuela, and H. taeniurus from Trinidad and adjacent mainland drainages in Venezuela) in having ii, 7, i dorsal-fin rays (vs. ii, 8). H. guejarensis is further distinguished from H. taeniurus and H. jabonero, in having a wider second pigment layer in the humeral spot (covering 3 vs. 2 scale widths). H. guejarensis is very similar to H. metae (an allopatric species also present in streams of the Orinoco River Basin in Venezuela and Colombia and some Venezuelan Caribbean drainages). Hemibrycon guejarensis is distinguishedby the orientation of the dorsal lateral-line canal which crosses the ventral part of the humeral spot transversely vs. horizontally across dorsal part of spot in the holotype of H. metae and Orinoco and Caribbean populations. H. guejarensis differs from H. metae in having the tip of the pectoral fin passing the pelvic-fin insertions (vs. pectoral fin tip not reaching pelvic-fin insertions). We identify populations previously considered as Hemibrycon metae from Venezuelan Orinoco River Basin piedmont streams and Caribbean drainages to be instead H. jabonero and H. taeniurus. Careful analysis of these populations indicated that all of them differ from the H. metae holotype and topotypic specimens in pelvic fin and postorbital lengths.

scholarly journals Size at morphological maturity of Ucides cordatus (Linnaeus, 1763) (Brachyura, Ocypodidae) in the Laranjeiras Bay, Southern Brazil

2005 ◽  
Vol 48 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Glaucia Dalabona ◽  
Jayme de Loyola e Silva ◽  
Marcelo Antonio Amaro Pinheiro
Keyword(s):  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Carapace Width ◽  
Southern Brazil ◽  
Monthly Basis ◽  
Ucides Cordatus ◽  
Size At Sexual Maturity ◽  
Males And Females ◽  
One Year

Morphometry and maturity of Ucides cordatus were analyzed with males and females collected during one year on a monthly basis at Laranjeiras Bay, Paraná State, Brazil. Carapace length, chelipeds propodus length and abdominal width were measured and related to carapace width to verify sexual dimorphism and size at morphological maturity of each sex. Carapace and propodus length of larger and smaller cheliped presented difference between sexes, confirming the use of both as secondary sexual characters. MATURE II program indicated 44mm and 43mm of carapace width to represent the size at sexual maturity of males and females, respectively.

scholarly journals Population biology of Uca mordax (Smith, 1870) (Crustacea, Decapoda, Ocypodidae) from the southeastern coast of Brazil

2009 ◽  
Vol 31 (73/75) ◽  
Author(s):  
Vivian Fransozo ◽  
Rafael Campanelli Mortari ◽  
Aline Staskowian Benetti
Keyword(s):  
Sex Ratio ◽  
Population Biology ◽  
Sexual Maturity ◽  
Fiddler Crab ◽  
Carapace Width ◽  
Southeastern Coast ◽  
Size Classes ◽  
Median Size ◽  
Size At Sexual Maturity ◽  
Males And Females

The population biology of the fiddler crab Uca mordax (Smith, 1870) was investigated in an estuarinemangrove from the southeastern coast of Brazil. Samplings were monthly performed by 2 collectors for30 min. using the technique of capture per unit effort during low tide periods. The allometric techniquewas used to determine crab size at sexual maturity (males and females). Thus, specimens were classified into juveniles and adults according to their size at sexual maturity for each sex. The specimens weredistributed into size classes. Recruitment was based on the juvenile frequency and the reproduction peakin ovigerous females. The median size of males was 15.9 ± 2.7 mm carapace width (CW) (n = 557) andthat of females, 14.6 ± 2.8 mm CW (n = 528). At sexual maturity, size of crabs was 11.9 mm CW formales and 11.5 mm CW for females. Juveniles were found throughout the year but more frequently inthe winter and autumn. Sex ratio did not differ among seasons, except during the summer (p < 0.05).As regards sex ratio per size class, females predominated in the fi rst size classes. Reproduction peakwas observed in the summer. In short, the population biology of U. mordax was similar to that of mostbroad-front fi ddler crab species.

scholarly journals Ukuran mesiodistal dan servikoinsisal gigi insisivus sentralis suku Bugis, Makassar, dan Toraja tidak menunjukkan perbedaan yang bermakna Size of mesiodistal and cervicoincisal maxillary central incisors between Buginese, Makassarese, and Torajanese showed no significant difference

2013 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Irene Edith Rieuwpassa ◽  
Nurlindah Hamrun ◽  
Fitrian Riksavianti
Keyword(s):  
T Test ◽  
The Other ◽  
Male And Female ◽  
Anova Test ◽  
Lower Jaw ◽  
Significant Difference ◽  
Males And Females ◽  
Average Size

Every tribe and race has size of tooth mesiodistal and cervicoincisal different from each other. The most obviousdifference is the size of the teeth between female and male. This study aimed to determine differences in size ofmesiodistal and cervicoincisal maxillary central incisors between male and female of Buginese, Makassarese andTorajanese. The sample consisted of 30 Buginese, 30 Makassarese, and 30 Torajanese aged frem 18-25 years-old.After impression of the upper and lower jaw was taken, and size of mesiodistal and cervicoincisal tooth weremeasured. After the data were analyzed by t-test and ANOVA test, it appears that males have a larger size thanfemales. Makassarese has the longest mesiodistal size (8.41 mm), Buginese has the longest cervicoincisal size (9.83mm), whereas Torajanese has the smallest size of mesiodistal and cervicoincisal among the other tribes. It was concluded that the average sizes of mesiodistal and cervicoincisal of maxillary central incisors showed no significantdifference. While there are significant differences in the average size of the mesiodistal and cervicoincisal maxillarycentral incisors between the males and females, and based on tribe lines.

Some Resemblances and Differences Between Raja erinacea and Raja ocellata, Including a Method of Separating Mature and Large-Immature Individuals of These Two Species

1965 ◽  
Vol 22 (4) ◽  
pp. 899-912 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
Sexual Maturity ◽  
Raja Erinacea ◽  
Male And Female ◽  
Immature Male ◽  
Size At Sexual Maturity ◽  
Raja Ocellata ◽  
Tooth Count

Raja erinacea Mitchill and Raja ocellata Mitchill are now distinguished by differences in tooth count and, in larger specimens, by size, size at sexual maturity, and eye spots when present in R. ocellata. The presence of distinct eye spots in the typical R. ocellata position in some R. erinacea was recorded. Separation of mature and large-immature male and female individuals of these two species was achieved by means of ventral pelvic denticles located in different positions in the two species, closer to the cloaca in female R. erinacea and more laterally on the pelvic fins in female R. ocellata. These pelvic denticles occur also in mature and maturing male R. ocellata but not in male R. erinacea. The denticles are much smaller and more numerous in R. erinacea and have relatively smaller sharp-angled bases with usually 4 and occasionally 5–6 rays. In R. ocellata the bases of the denticles are usually much larger, have 4–11 or more rays, usually with rounded tips.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS:

1968 ◽  
Vol 58 (4) ◽  
pp. 600-612 ◽  
Author(s):  
Robert Boyd ◽  
Donald C. Johnson
Keyword(s):  
Ascorbic Acid ◽  
Testosterone Propionate ◽  
Female Rats ◽  
Female Rat ◽  
Feedback Effects ◽  
Male And Female ◽  
Prostate Weight ◽  
Male And Female Rats ◽  
Males And Females ◽  
Normal Males

ABSTRACT The effects of various doses of testosterone propionate (TP) upon the release of luteinizing hormone (LH or ICSH) from the hypophysis of a gonadectomized male or female rat were compared. Prostate weight in hypophysectomized male parabiotic partners was used to evaluate the quantity of circulating LH. Hypophyseal LH was measured by the ovarian ascorbic acid depletion method. Males castrated when 45 days old secreted significantly more LH and had three times the amount of pituitary LH as ovariectomized females. Administration of 25 μg TP daily reduced the amount of LH in the plasma, and increased the amount in the pituitary gland, in both sexes. Treatment with 50 μg caused a further reduction in plasma LH in males, but not in females, while pituitary levels in both were equal to that of their respective controls. LH fell to the same low level in partners of males or females receiving 100 μg TP. When gonadectomized at 39 days, males and females had the same amount of plasma LH, but males had more stored hormone. Pituitary levels were unchanged from controls following treatment with 12.5, 25 or 50 μg TP daily, but plasma values dropped an equal amount in both sexes with the latter two doses. Androgenized males or females, gonadectomized when 39 days old, were very sensitive to the effects of TP and plasma LH was significantly reduced with 12.5 μg daily. Pituitary LH in androgenized males was higher than that of normal males but was reduced to normal by small amounts of TP. The amount of stored LH in androgenized females was not different from that of normal females and it was unchanged by any dose of TP tested. Results are consistent with the conclusion that the male hypothalamic-hypophyseal axis is at least as sensitive as the female axis to the negative feedback effects of TP. Androgenization increases the sensitivity to TP in both males and females.

New records of Ephemeroptera from the Colombian Orinoco river basin of the Meta department

2017 ◽  
Vol 43 (2) ◽  
pp. 271
Author(s):  
Luis Gonzalo Salinas-Jiménez ◽  
José Ismael Rojas-Peña ◽  
Diana Paola Osorio-Ramírez ◽  
Clara Inés Caro-Caro
Keyword(s):  
River Basin ◽  
New Records ◽  
Andean Region ◽  
Orinoco River ◽  
First Time

There is extensive research of the Ephemeroptera communities taxonomy and ecology in the Andean region of Colombia. However, other regions such as the Orinoquia have been insufficiently studied. From this region, in the Meta department, four species have been registered: Varipes lasiobrachius Lugo-Ortiz & McCafferty, Coryphorus aquilus Peters, Miroculis (Atroari) colombiensis Savage & Peters and Tricorythopsis rondoniensis (Dias, Cruz & Ferreira). The main objective of this study is to report for the first time for this region the species: Mayobaetis ellenae (Mayo), Hydrosmylodon primanus (Eaton), Haplohyphes baritu Domínguez, Camelobaetidus edmundsi Dominique, Mathuriau & Thomas and Nanomis galera Lugo-Ortiz & McCafferty.

Gender Differences in Clothing Worn in Current Popular Comic Books

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Kyle Landon Jossy
Keyword(s):  
Gender Differences ◽  
Content Analysis ◽  
Comic Books ◽  
Book Industry ◽  
Comic Book ◽  
Lower Body ◽  
Female Characters ◽  
Male And Female ◽  
Males And Females

This study looked at how males and females were portrayed, based on the amount of skin shown in the clothing worn.  A Content analysis was performed on a sample of 20 randomly selected popular comics from the last 3 years.  Both male and female characters were rated on how much skin they showed in three clothing categories; neck line, sleeve length, and lower body.  Results showed that in all 3 categories, women consistently wore more revealing clothing.  The findings demonstraetd that the comic book industry is comparable to other forms of media, in the sexualization of female characters, by having them wear more revealing clothing.

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