Population structure, fecundity and embryo loss of the sea grass shrimp Latreutes pymoeus (Decapoda: Hippolytidae) at Inhaca Island, Mozambique

2007 ◽  
Vol 87 (4) ◽  
pp. 879-884 ◽  
Author(s):  
Gil Penha-Lopes ◽  
Paulo Torres ◽  
Adriano Macia ◽  
José Paula
Keyword(s):  
Population Structure ◽  
Brood Size ◽  
Carapace Length ◽  
Grass Shrimp ◽  
Stage Iv ◽  
Development Stage ◽  
Size Class ◽  
Morphometric Measurements ◽  
Sea Grass ◽  
Males And Females

Latreutes pymoeus is a poorly studied tropical and sub-tropical shrimp species that mainly lives on sea grass beds. Samples were collected from sea grass beds of Inhaca Island, Mozambique, during August 2005 at neap/spring and low/high tides. Specimens were identified, sexed, counted and morphometric measurements were made. Ovigerous females were classified as small (carapace length (CL): 2.7–3.2 mm), medium (CL: 3.3–3.8 mm) and large (CL: 3.9–4.4 mm). Embryo masses were carefully removed from the pleopods with forceps, eggs staged and counted. On average, about 20% more males were found than females (0.64 ±0.25 and 0.56 ±0.28 ind m-2, respectively), but males were significantly smaller (2.25 ±0.32 and 2.60 ±0.47 mm CL for males and females, respectively). At 3.1 mm CL at least 50% of the females found carried embryos in the pleopods. Average (±SD) brood size increased significantly with female length (76 ±18, 133 ±64 and 205 ±61, for small, medium and large ovigerous females). The number of embryos decreased significantly over the incubation period for each size-class of the shrimp. Brood loss from embryonic Stage I to Stage IV for small, medium and large shrimp were 19.8%, 36.5% and 41.8%, respectively. Although an increase in brood loss was observed with increasing shrimp size, senescence did not seem to occur since larger shrimps carried a higher number of embryos and negative allometry was not recorded. Mean embryo volume, in the same development stage, was not significantly different among the small, medium and large shrimp, increasing significantly from 0.014 mm3 to 0.029 mm3 from the first to last embryonic stages.

Seasonal variation on embryo production and brood loss in the Monaco shrimp Lysmata seticaudata (Decapoda: Hippolytidae)

2003 ◽  
Vol 83 (5) ◽  
pp. 959-962 ◽  
Author(s):  
R. Calado ◽  
L. Narciso
Keyword(s):  
Brood Size ◽  
Egg Production ◽  
Sex Change ◽  
Development Stage ◽  
Size Class ◽  
Reproductive Season ◽  
Embryonic Stage ◽  
Embryo Production ◽  
Major Period ◽  
Stage 1

The Monaco shrimp Lysmata seticaudata is a warm temperate species with strong potential for the marine aquarium industry and knowledge on embryo production and brood loss during incubation is essential for the establishment of proper maturation techniques. Average (±SD) brood size of small (total length (TL) 40–44 mm), medium (TL 48–52 mm) and large (TL 58–62 mm) simultaneous hermaphroditic (SH) phase were 753 (±215), 1351 (±163) and 1810 (±264) newly extruded embryos, respectively, in early reproductive season (ERS); and 745 (±258), 1314 (±191) and 1813 (±219), respectively, in late reproductive season (LRS). Senescence does not seem to occur in the Monaco shrimp, since during both ERS and LRS larger SH shrimp always presented a higher number of embryos and negative allometry was not recorded. No significant differences in brood size were recorded among broods at different embryonic stages of shrimp in the same size-class in both ERS and LRS. Brood losses recorded from embryonic Stage 1 to Stage 4 for small, medium and large shrimp were 14.3%, 11.3% and 8.9%, respectively, for ERS and 10.9%, 14.4% and 12.2%, respectively, for LRS. The mean embryo volume in the same development stage was not significantly different among the small, medium and large shrimp, and between ERS and LRS for shrimp of same size-class. For all shrimp size-classes during both ERS and LRS, mean embryo volume significantly increased from 108.5% to 127.9%, from first to last embryonic stage. The occurrence of sex change does not affect egg production since small females in ERS (before the major period of sex change) and LRS (after the major period of sex change) had similar brood sizes.

scholarly journals Method of capture and population structure of Aegla georginae Santos and Jara, 2013 (Decapoda: Anomura: Aeglidae) in a tributary of the Ibicuí River in southern Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 1035-1042 ◽  
Author(s):  
C. E. Copatti ◽  
R. P. Legramanti ◽  
A. Trevisan ◽  
S. Santos
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
River Basin ◽  
Frequency Distribution ◽  
Relative Abundance ◽  
Carapace Length ◽  
Grouped Data ◽  
Southern Brazil ◽  
Size Classes ◽  
Males And Females

Abstract In the current study, we investigated population aspects of Aegla georginae in the Ibicuí River Basin by considering different capture methods and the implication of these data in the analysis of population dynamics. We sampled 1774 individuals: 1259 males (21 and 97 juveniles and 1029 and 113 adults in trap and handnet, respectively), 512 females (05 and 140 juveniles, 184 and 64 adults, and 81 and 38 ovigerous in trap and handnet, respectively) and 03 unsexed individuals (02 and 01 in trap and handnet, respectively). The frequency distribution in size classes shows a bimodal model for both sexes. The carapace length (CL) in males and females varied from 3.11 to 26.00 and 3.73 to 22.36 mm, respectively. Males presented significantly larger sizes than females. The relative abundance between males and females was significantly different from 1:1 with more males than females in most sampling periods (p < 0.05) when considering the grouped data (handnet + trap) and trap captures, but followed the expected ratio in most months when considering individuals sampled only with handnet (p > 0.05). Juveniles were recorded in all seasons, and reproduction occurs throughout the year. The population structure is similar to the model known for aeglids, and the capture methods affected the analysis of A. georginae, where the grouped data and trap captures presented greater abundance of individuals than handnet and males predominate in the larger size classes, and females in the intermediary size classes. Therefore, an integrated view of the capture methods is the best model for studying the population dynamics of aeglids.

scholarly journals Population structure of Macrobrachium amazonicum (Heller, 1862) (Decapoda: Palaemonidae) in Miranda Hydroelectric Plant Reservoir, Araguari river, Minas Gerais, Brazil

2019 ◽  
Vol 31 ◽  
Author(s):  
Raquel Costa e Silva ◽  
Marina Calixto Cunha ◽  
Emerson Contreira Mossolin ◽  
Giuliano Buzá Jacobucci
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Carapace Length ◽  
Hydroelectric Plant ◽  
Size Variation ◽  
Minas Gerais ◽  
Size Class ◽  
Size Frequency Distribution ◽  
Reproduction Strategy ◽  
Continuous Reproduction

Abstract Aim The present study aimed to analyze a M. amazonicum population structure in a reservoir of the “Triângulo Mineiro”, Brazil. Methods Monthly surveys were carried out from April/2012 to May/2013 at the Miranda Hydroelectric Plant Reservoir located in Araguari river, state of Minas Gerais. A sampling section of 100 m long, 5 m wide and depth not exceeding 1 m was defined on the banks of the reservoir. Sampling consisted on two persons quickly passing a 2 mm sieves in partially submerged marginal vegetation, for one hour. The sampled specimens were identified, sexed and measured. Results A total of 2,584 specimens were analyzed, of which 64.62% were females (3.93% ovigerous, 5.94% non-ovigerous and 54.75% juveniles), 29.16% males (21.41% adults and 7.76% juveniles) and 6.22% juveniles of undetermined sex. The sex ratio (1:2.21) indicated a clear deviation for females, for the whole sampling period, monthly and for each size class. Males had an average carapace length (CL = 4.50 ± 0.71 mm) significantly lower than females (CL = 4.64 ± 1.47 mm) and the size frequency distribution revealed a unimodal pattern, with peaks occurring in 4.0 - 4.9 mm size class for males and in 3.0 - 3.9 mm size class for females. The relation between total and carapace length was significant, indicating a negative allometric growth. No males’ morphotypes were found. The population presented a continuous reproduction with a gradual increase between April and June/2012. Female sexual maturity was determined for 6.3 mm of CL, while for males was estimated for 4.0 mm. Conclusion The Miranda reservoir population had a body size variation similar to the continental populations of Pantanal. The sexual dimorphism observed may be related to the absence of male morphotypes and to the “pure search” reproduction strategy. The deviated sex ratio for females may increase the chance of fertilization and the reproductive success. The presence of juveniles and ovigerous females throughout the year indicates a continuous reproduction pattern of the population.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Microsatellite population structure of Newfoundland black bears (Ursus americanus hamiltoni)

2011 ◽  
Vol 89 (9) ◽  
pp. 831-839 ◽  
Author(s):  
H. Dawn Marshall ◽  
Edward S. Yaskowiak ◽  
Casidhe Dyke ◽  
Elizabeth A. Perry
Keyword(s):  
Population Structure ◽  
Ursus Americanus ◽  
Intraspecific Variability ◽  
Black Bears ◽  
Postglacial Colonization ◽  
Correct Assignment ◽  
Hair Samples ◽  
Males And Females ◽  
Two Populations ◽  
F Statistics

We investigated population structure of black bears ( Ursus americanus hamiltoni Cameron, 1957) from insular Newfoundland using the microsatellite profiles of 12 loci from three broadly distributed areas (Northern, Baie Verte, and Bonavista peninsulas). Our goals were to revisit earlier findings of low heterozygosity in Newfoundland and increase knowledge of intraspecific variability in black bears, and make inferences about postglacial colonization and contemporary movements of island black bears. Ninety-three individuals (42 males) were identified among 543 hair samples: 21 from Bonavista, 25 from Northern Peninsula, and 47 from Baie Verte. Genetic diversity is relatively low (HE = 0.42) and decreases from northwest to southeast. Small but significant subpopulation differentiation revealed by F statistics is greatest between Northern and Baie Verte peninsulas; it is lower and comparable in the remaining pairwise comparisons. We hypothesize that postglacial colonization proceeded from the Northern Peninsula southeastward. Bears migrated from the Northern Peninsula to Baie Verte at some more distant time in the past, then diverged by genetic drift. More recently, migration occurred from these two populations to Bonavista, characterized by positive FIS indicative of admixture. Tests of biased dispersal and posterior probability of correct assignment to locality reveal contemporary movements of both males and females with historical dispersal attributable to males.

scholarly journals The gravireceptor of Phycomyces. Its development following gravity exposure.

1984 ◽  
Vol 84 (6) ◽  
pp. 845-859 ◽  
Author(s):  
D S Dennison ◽  
W Shropshire
Keyword(s):  
Spatial Relationship ◽  
Stage Iv ◽  
Development Stage ◽  
Stage Ii ◽  
Stage Iii ◽  
Mature Stage ◽  
Early Exposure ◽  
Altered Gravity

The gravitropism of a mature stage IV Phycomyces sporangiophore has a shorter and more uniform latency if the sporangiophore is exposed horizontally to gravity during its earlier development (stage II and stage III). This early exposure to an altered gravitational orientation causes the sporangiophore to develop a gravireceptor as it matures to stage IV and resumes elongation. A technique has been developed to observe the spatial relationship between the vacuole and the protoplasm of a living sporangiophore and to show the reorganization caused by this exposure to altered gravity. Possible gravireceptor mechanisms are discussed.

VARIATION, SEXUAL DIMORPHISM, AND MATURITY IN A QUEBEC POPULATION OF THE COMMON SNAPPING TURTLE, CHELYDRA SERPENTINA

1960 ◽  
Vol 38 (1) ◽  
pp. 19-38 ◽  
Author(s):  
James E. Mosimann ◽  
J. Roger Bider
Keyword(s):  
Carapace Length ◽  
Relative Rate ◽  
Analysis Of Covariance ◽  
Head Width ◽  
Posterior Lobe ◽  
Chelydra Serpentina ◽  
Single Population ◽  
Species Analysis ◽  
The Common ◽  
Males And Females

An analysis was made of a sample of 55 snapping turtles, Chelydra serpentina, from a single locality in southern Quebec. The variation studied is regarded as being representative of that of a single population of the species. Analysis of covariance was used in studying dimorphism in various measurements. Conclusions reached are: (a) the sex ratio is one; (b) males grow to a larger size than females; (c) males and females become mature at a carapace length of about 200 millimeters; (d) the ratio precloacal distance over posterior lobe of the plastron gives a practical index for sex determination in adults; (e) there is a set of small but interrelated changes correlated with a greater precloacal distance in the male: These are that males have the plastron shifted forward slightly, have the bridge slightly longer relative to plastron length, and have the posterior lobe of the plastron slightly shorter relative to plastron length; (f) the precloacal length of the male (which area accommodates the penis) grows relatively faster than carapace length; the precloacal length of the female grows at the same relative rate as carapace length; (g) there is virtually no dimorphism in shell dimensions nor in head width.

scholarly journals A multivariate study of variation in two species of rock crab of the genus Leptograpsus

1974 ◽  
Vol 22 (3) ◽  
pp. 417 ◽  
Author(s):  
NA Campbell ◽  
RJ Mahon
Keyword(s):  
Carapace Length ◽  
Carapace Width ◽  
The Body ◽  
Canonical Variate ◽  
Multivariate Approach ◽  
Maximum Width ◽  
Multivariate Study ◽  
Rock Crab ◽  
Males And Females ◽  
Colour Form

A multivariate approach has been used to study morphological variation in the blue and orange-form species of rock crab of the genus Leptograpsus. Objective criteria for the identification of the two species are established, based on the following characters: width of the frontal region of the carapace; width of the posterior region of the carapace (rear width); length of the carapace along the midline; maximum width of the carapace; and the depth of the body. The first canonical variate, which differentiates between the two species, represents a contrast between the carapace width relative to the width of the front lip and the depth of the body; the blue-form species has a greater relative carapace width than has the orange form. The second canonical variate, which presents a contrast between the rear width and the carapace length, identifies males and females within each species; males have a greater relative carapace length than have females. All individuals, including 20 not used in the study, were correctly identified for colour form. The clear separation of the blue and orange forms achieved by canonical analysis supports the previously determined specific status of the two forms.

Assessment of ocean acidification and warming on the growth, calcification, and biophotonics of a California grass shrimp

2017 ◽  
Vol 74 (4) ◽  
pp. 1150-1158 ◽  
Author(s):  
Kaitlyn B. Lowder ◽  
Michael C. Allen ◽  
James M. D. Day ◽  
Dimitri D. Deheyn ◽  
Jennifer R. A. Taylor
Keyword(s):  
Ocean Acidification ◽  
Environmental Conditions ◽  
Spectral Reflectance ◽  
Visual Communication ◽  
Carapace Length ◽  
Grass Shrimp ◽  
Ocean Warming ◽  
Increased Temperature

Cryptic colouration in crustaceans, important for both camouflage and visual communication, is achieved through physiological and morphological mechanisms that are sensitive to changes in environmental conditions. Consequently, ocean warming and ocean acidification can affect crustaceans’ biophotonic appearance and exoskeleton composition in ways that might disrupt colouration and transparency. In the present study, we measured growth, mineralization, transparency, and spectral reflectance (colouration) of the caridean grass shrimp Hippolyte californiensis in response to pH and temperature stressors. Shrimp were exposed to ambient pH and temperature (pH 8.0, 17 °C), decreased pH (pH 7.5, 17 °C), and decreased pH/increased temperature (pH 7.5, 19 °C) conditions for 7 weeks. There were no differences in either Mg or Ca content in the exoskeleton across treatments nor in the transparency and spectral reflectance. There was a small but significant increase in percent growth in the carapace length of shrimp exposed to decreased pH/increased temperature. Overall, these findings suggest that growth, calcification, and colour of H. californiensis are unaffected by decreases of 0.5 pH units. This tolerance might stem from adaptation to the highly variable pH environment that these grass shrimp inhabit, highlighting the multifarious responses to ocean acidification, within the Crustacea.

scholarly journals Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Yenni Arista ◽  
ZAIRION ◽  
YUSLI WARDIATNO
Keyword(s):  
Population Dynamics ◽  
Population Structure ◽  
Life Span ◽  
Fishery Resource ◽  
Growth Coefficient ◽  
Mantis Shrimp ◽  
Exploitation Rate ◽  
L Value ◽  
Males And Females

Abstract. Ekalaturrahmah YAC, Zairon, Wardiatno Y. 2020. Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia. Biodiversitas 21: 1458-1466. Mantis shrimps are a potential fishery resource in Indonesia, but information about their population dynamics in the southern waters of Madura is limited. This study aimed to determine the population structure, growth, life span, and rate of exploitation for two taxa of mantis shrimp (Harpiosquilla harpax and Oratosquillina sp.). The research was conducted from September 2018 to February 2019 in the southern waters of Madura. The results showed that for H. harpax the majority of males caught ranged in length between 132.50 and 139.37 mm while the majority of females were between 153.45 and 160.22 mm. For Oratosquillina sp., the majority of males caught ranged from 84.70 and 89.60 mm while the majority of females were between 89.85 and 95.30 mm. The Growth Coefficient (K) for H. harpax was estimated to be 0.65 per year for males and 0.60 per year for females; while for Oratosquillina sp. the estimates were 0.81 and 0.78 per year, respectively. The L∞ value for H. harpax males was 183.00 mm and for females 250.55 mm, while the L∞ values for Oratosquillina sp. were 112.64 mm for males and 137.02 for females. The life span of H. harpax was estimated at 5 years, while for Oratosquillina sp. it was 4 years. The exploitation rate (E) for H. harpax males and females was 0.65 and 0.67 respectively, while for Oratosquillina sp. it was 0.54 and 0.58. These estimations indicated overexploitation of the resource, particularly in the case of H. harpax.

Sign in / Sign up

Export Citation Format

Share Document