Age, growth and maturation of the loliginid squids Alloteuthis africana and A. Subulata on the west African shelf

1993 ◽  
Vol 73 (4) ◽  
pp. 949-961 ◽  
Author(s):  
Alexander Arkhipkin ◽  
Nataly Nekludova
Keyword(s):  
Body Weight ◽  
Continental Shelf ◽  
Life Span ◽  
West African ◽  
The Body ◽  
The West ◽  
Growth Increments ◽  
Wide Range ◽  
Growth Zones

Samples of two loliginid squids Alloteuthis africana and A. subulata were collected from the continental shelf off the west Sahara in August-September 1987. Statoliths were taken from 124 specimens and processed using statolith ageing techniques. Statoliths of both species were very similar in shape. In the ground statolith, growth increments were examined and grouped into four growth zones distinguished mainly by the width of the increments. Age of adult mature males of both species did not exceed eight months, that of females six months. Alloteuthis africana grew faster than A. subulata in weight and, particularly, in length. At age 180 d the mantle of A. africana was twice as long and the body weight 1·2–1·5 times as large. Both species matured over a wide range of sizes and ages (from 120 to 180 d). The life span of A. africana and A. subulata hatching between January and May on the west Saharan shelf is about six months, much shorter than that of A. subulata in its northern temperate range.

Assessing Bypassed Hydrocarbons

2021 ◽  
Author(s):  
Stanley Oifoghe ◽  
Nora Alarcon ◽  
Lucrecia Grigoletto
Keyword(s):  
Continental Shelf ◽  
Reservoir Characterization ◽  
Gamma Ray ◽  
West African ◽  
The Novel ◽  
The West ◽  
Present Case Study ◽  
Novel Model

Abstract Hydrocarbons are bypassed in known fields. This is due to reservoir heterogeneities, complex lithology, and limitations of existing technology. This paper seeks to identify the scenarios of bypassed hydrocarbons, and to highlight how advances in reservoir characterization techniques have improved assessment of bypassed hydrocarbons. The present case study is an evaluation well drilled on the continental shelf, off the West African Coastline. The targeted thin-bedded reservoir sands are of Cenomanian age. Some technologies for assessing bypassed hydrocarbon include Gamma Ray Spectralog and Thin Bed Analysis. NMR is important for accurate reservoir characterization of thinly bedded reservoirs. The measured NMR porosity was 15pu, which is 42% of the actual porosity. Using the measured values gave a permeability of 5.3mD as against the actual permeability of 234mD. The novel model presented in this paper increased the porosity by 58% and the permeability by 4315%.

Age structure and life cycles of the Argentine shortfin squid Illex argentinus (Cephalopoda: Ommastrephidae) in southern Brazil

2012 ◽  
Vol 93 (2) ◽  
pp. 557-565 ◽  
Author(s):  
R. Schwarz ◽  
J.A.A. Perez
Keyword(s):  
Life Cycle ◽  
Age Structure ◽  
Life Cycles ◽  
Southern Brazil ◽  
Trawl Fishery ◽  
Growth Increments ◽  
Wide Range ◽  
Growth Zones ◽  
Illex Argentinus ◽  
Post Spawning

Age structure and hatchling dates of the squid Illex argentinus collected by bottom-trawl fishery in southern Brazilian waters were assessed by the analysis of statolith growth increments. Catches occurred between 2001 and 2002, from 23° to 32°S at depths of 100–700 m. Squid from juvenile to post-spawning stages were collected year round, with age estimated from 98 to 320 days and mantle lengths ranging from 112 to 376 mm. Duration of life cycle events based on statolith growth zones revealed that squids can spend about 14% of their lifespan as paralarva (~30 days), 70% as juvenile (~130 days), leaving maturity and spawning condition to the terminal 10–20% (~30–60 days). The results suggest that, unlike estimates available for Patagonian populations, a general 0.5 year lifespan is predicted for I. argentinus off Brazil. The wide range of size-at-ages implied that catches of shortfin squid off southern Brazil probably include squid hatched throughout the year. Mature and spawning squid caught in summer months hatched in winter and spring, while winter catches revealed mature-spawning individuals hatched both in summer/autumn (~6 months of age) and winter/spring periods (~10–11 months of age). It has been argued that such groups may combine both squid resident of Brazilian outer shelf and slope (22°–34°S) with a six months' lifespan and migrating squid originated from the northern Patagonian shelf (~42°S) with 10–11 months' lifespan.

scholarly journals Homicide and corpse dismemberment: A study of one case

2021 ◽  
Vol 8 (4) ◽  
pp. 251-254
Author(s):  
C BIGOT ◽  
F O NGONGANG ◽  
E NSEME ◽  
M SOUMAH ◽  
Z SANDO
Keyword(s):  
Cutting Planes ◽  
West African ◽  
The Body ◽  
Public Place ◽  
Criminal Offence ◽  
The West ◽  
Development Context ◽  
Plastic Bag ◽  
African Context ◽  
Mechanical Asphyxia

Homicide may be an isolated impulsive act arising from a situation or based on a previous conception, which is premeditation. Despite its nature or motivations, homicide remains a wrongful criminal act at all times and in all places. Several studies conducted in Western countries on this topic have highlighted the overriding concern of the criminal, which includes concealing the criminal offence in most cases.In Africa, apart from cases of infanticide, the discovery of the body of a homicide victim in a public place is a relatively common phenomenon, particularly if it involves mutilation.The body was examined; it was a young adult African female whose corpse was wrapped in a plastic bag. The autopsy established that the section or cutting planes were preferably lodged in the large joints.Death was caused by mechanical asphyxia. The focus of this case lies in the atypical nature of this type of postmortem manipulation in the West African context.The unusual nature of this type of homicide illustrates and underscores some reality in our development context.

scholarly journals Cambios y Evolución de las Pesquerías en al Atlántico Centro-Oriental

1973 ◽  
Vol 30 (12) ◽  
pp. 2301-2307
Author(s):  
C. Bas
Keyword(s):  
Species Composition ◽  
Primary Production ◽  
Continental Shelf ◽  
West African ◽  
Biological Characteristics ◽  
Marine Fisheries ◽  
The West ◽  
West African Coast ◽  
African Coast ◽  
Very High

This paper deals with the marine fisheries off the West African coast, between the Straits of Gibraltar and Mauritania, an area which is characterized by its relatively narrow continental shelf, the presence of the Canary Current, and intensive upwelling resulting in very high primary production and rich bottom fauna.The main fisheries (for sardines, sardinellas, hakes, sparids, cephalopods, and demersal crustaceans) are analyzed with regard to their evolution, species composition, fishing areas and seasons, the biological characteristics of the exploited stocks, and the effect of fishing on them.The criteria to be considered when planning the control and regulation of these fisheries are also analysed.

scholarly journals A preliminary report on the production characters of three types of cattle in Ghana.

1963 ◽  
Vol 11 (5) ◽  
pp. 364-377
Author(s):  
G. Montsma
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Agricultural Research ◽  
West African ◽  
Research Station ◽  
Insufficient Data ◽  
The West ◽  
Weight Growth ◽  
Before And After ◽  
The University

At the University of Ghana's Agricultural Research Station at Nungua observations were begun in 1957 on the performance of West African Shorthorn, N'Dama and Sokoto Gudali cattle. The main preliminary findings are discussed under the following headings: body weight, growth rate, milk yield, reproductive efficiency, and dentition and age. In spite of the fact that the N'Dama and West African Shorthorn are naturally small animals, body weight and growth rate could be substantially increased by better feeding. Insufficient data are as yet available on the Sokoto. Under the better-than-average feeding conditions at the station, av. body weight at 8 mths. was 305 lb. in the N'Dama, 340 lb. in the West African Shorthorn, and 470 lb. in the Sokoto. Maximum body weight at 8 mths. was 340, 360 and 550 lb. resp. In animals fed a concentrate supplement, av. 252-day milk yields per 100 lb. body weight were 295, 300 and 335 lb. for the N'Dama, West African Shorthorn and Sokoto resp. max. yields, expressed in a similar manner, being 416, 430 and 458 lb. resp. Milk yields were estimated by weighing the calves before and after suckling thrice daily for approx. 20 mins The av. calving percentages for the 3 breeds were 85, 83 and 76 resp. which are equivalent to calving intervals of 14-2, 14.5 and 15.8 mths. The av. age at 1st calving in the West African Shorthorn was estimated to be 3 yrs. (2.3-3.8). Insufficient data were available on the other 2 breeds. It is considered that, if adequately fed, heifers are capable of calving at 27-30 mths. of age. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Addressing the Vepris verdoorniana complex (Rutaceae) in West Africa, with two new species

Kew Bulletin ◽  
2019 ◽  
Vol 74 (4) ◽  
Author(s):  
Martin Cheek ◽  
Jean-Michel Onana ◽  
Shigeo Yasuda ◽  
Poppy Lawrence ◽  
Gabriel Ameka ◽  
...  
Keyword(s):  
New Species ◽  
Deciduous Forest ◽  
Distinct Species ◽  
West African ◽  
Strict Sense ◽  
Original Material ◽  
The West ◽  
Wide Range ◽  
Variable Species ◽  
Mining Projects

Summary Vepris verdoorniana (Rutaceae) has long been regarded as a widespread and variable species occurring from Guinea to Gabon. Recent evidence has shown that the original material from the type locality in Cameroon consists of two different species, V. verdoorniana in the strict sense, endemic to Lower Guinea (Cameroon, Gabon and C.A.R. in W-C Africa) and V. letouzeyi Onana, which was thought to occur from Guinea to Cameroon. In this paper we show that the West African (Upper Guinea) material previously referred to as V. letouzeyi/V. verdoorniana is separate morphologically from that in Cameroon (Lower Guinea). In fact the West African material referred to comprises two distinct species, here described as V. occidentalis Cheek & Onana (Guinea to Ghana, but probably extending to Benin) a tree of lowland marginal dry evergreen and semi-deciduous forest, and V. fer Cheek, a species restricted to four mainly lower submontane forest locations on iron substrates in Liberia and Sierra Leone (also Upper Guinea). Vepris occidentalis is here assessed as Least Concern due to its wide range and high frequency, whilst V. fer is assessed as Endangered due to the low number of locations and threats from iron ore mining projects. Both new species are illustrated and mapped.

scholarly journals Age and growth of two sympatric squid Loligo vulgaris and Loligo forbesi, in Galician waters (north-west Spain)

1999 ◽  
Vol 79 (4) ◽  
pp. 697-707 ◽  
Author(s):  
F. Rocha ◽  
A. Guerra
Keyword(s):  
Body Weight ◽  
Sexual Dimorphism ◽  
Life Span ◽  
Growth Patterns ◽  
Mantle Length ◽  
Age And Growth ◽  
North West ◽  
Loligo Vulgaris ◽  
Growth Increments ◽  
One Year

Age and growth of Loligo vulgaris and L. forbesi were studied by the examination of growth increments in 96 and 135 selected (white zone <10%) statoliths, respectively. Squid were obtained by monthly sampling from the catches of commercial trawling and hand-jigs in Galician waters (north-west Spain) between February 1991 and October 1993. Mantle length (ML) of L. vulgaris ranged from 70 to 480 mm and varied between 70 and 685 mm in L. forbesi. A negative allometry between statolith length and ML or body weight (BW) was found in both species. Sexual dimorphism was apparent in both species, males grew faster and longer than females. The statolith analysis suggests that growth patterns of L. vulgaris and L. forbesi in Galician waters are different. The exploited population of L. vulgaris was composed of two groups: one formed by individuals hatched in winter–spring and another by specimens hatched in summer–autumn. Squid hatched in winter–spring reached larger sizes at the same age than those hatched in summer–autumn. These two groups were also observed in L. forbesi. However, squid of this species hatched in winter–spring were smaller than those hatched in summer–autumn at the same age. Reasons for this discrepancy are discussed. The life span of L. vulgaris was about one year whereas the life span of L. forbesi extended to 18 months.

scholarly journals PENGARUH PEMBERIAN EKSTRAK ETANOL JAHE MERAH (Zingiber Officinale Roxb var Rubrum) TERHADAP KUANTITAS DAN KUALITAS SPERMATOZOA MENCIT JANTAN (Mus musculus L.) YANG DIINDUKSI PARAQUAT DIKLORIDA

2019 ◽  
Vol 5 (2) ◽  
pp. 47-54
Author(s):  
Dian Anggraini ◽  
Sutyarso Sutyarso ◽  
M. Kanedi ◽  
Hendri Busman
Keyword(s):  
Body Weight ◽  
Mus Musculus ◽  
Sperm Count ◽  
Zingiber Officinale ◽  
The Body ◽  
Test Material ◽  
Control Group ◽  
Ginger Extract ◽  
Wide Range ◽  
Red Ginger

Paraquat is one of the chemicals that contributes to increasing pollution Indonesia. The careless use of paraquat can increase production of ROS (Reactive Oxygen Species), resulting in damage to a wide range of vital organs and reproductive system disorders such as infertility. ROS in the body can be captured by antioxidants. Red Ginger contains high antioxidants because there are active phenolic compounds such as gingerol, shagaol, zingeron, ginggerdiol, and zingibren which are proven to protect body cells from damage caused by ROS. This study was aimed to test the effectiveness of red ginger extract (Zingiber officinale Roxb. Var. Rubrum) on the quantity and quality of sperm in male mice (Mus musculus L.) induced by paraquat dichloride.This research uses a completely randomized design and is divided into six treatment groups with each four replications: K1 as the control group (only given H2O); K2 (paraquat induced a dose of 20 mg/kg Body Weight (BW) without the administration of the test substances); K3; K4; K5 (paraquat induced a dose of 20 mg/kg Body Weight (BW) and was given a red ginger extract at a dose of consecutive succession 6 mg / ml, 12 mg / ml, 18 mg / ml) and K6 (Only given a test material the red ginger extract as much as 18 mg / ml). Paraquat was given 2 times a week for 21 days and the red ginger extract was given for 35 days. The results of analysis by One-way ANOVA followed LSD at 5% significance level showed the ethanolic extract of red ginger can increase the sperm count, motility, viability and Morphology sperm of mice induced by the paraquat diklorida.

scholarly journals Genetic and non-genetic factors affecting the performance of West African Dwarf (WAD), Yankasa (YAN) and WAD X YAN lambs in the tropics

2021 ◽  
Vol 41 (2) ◽  
pp. 44-52
Author(s):  
O. O. Adewumi
Keyword(s):  
Body Weight ◽  
Body Length ◽  
Rainy Season ◽  
Genetic Factors ◽  
West African ◽  
The Body ◽  
Genetic Group ◽  
Leg Length ◽  
Factors Affecting ◽  
West African Dwarf

Genetic and non-genetic factors affecting performance of sheep at the Teaching and Research farm of the Federal University of Technology, Akure, Ondo State, Nigeria were studied from 2005-2006. Genetic groups involved were 8 West African Dwarf sheep (WAD), 10 Yankasa (YAN) and 10 WAD X YAN (XBD). Data were analysed using General Linear Model of least squares analysis of variance to test the influence of genetic group, sex, season and age on weights and linear body measurements such as height at withers (HT), body length (BL), Neck length (NL), Neck circumference (NC), heart girth (HG), Foreleg length (FL), Hind leg length (HL), Face length (FA), Ear length (EA), Headwidth (HW), shoulder width (SW), tail length (TL) and Rump height (RH). Weight, HT, BL, HG, FL, HL, FL, EL, TL and RH were significantly affected by genetic group. Female lambs weighed 0.75kg more than the males (p<0.01). Season of birth had significant effect on WT (p<0.0001), HT (p<0.01), NL (p<0.001), FL (p<0.0001), HL (p<0.0.0001), FA (p<0.01), SW (p<0.01) and RL (p<0.05), the traits were superior in the rainy season. Age significantly affected all parameters considered. The WAD (0.53) and XBD (1.39kg) lambs were and heavier during the rainy season as compared to the dry season. Of the body dimensional traits, HG had the highest correlation coefficients with WT in WAD and YAN lambs estimated at 0.86 and 0.89 respectively, whereas HT was the most correlated trait with WT in XBD lambs. Height at withers and body length were the most important additional variables to heartgirth accounting for 87% prediction of body weight in WAD and YAN lambs, whereas, HT, BL, NC, HG, SW, TL and RH could account for up to 90% of body weight in XBD lambs

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