First substantial records of Physiculus dalwigki (Moridae) from the coast of Senegal (Eastern Tropical Atlantic)

The capture of two specimens of Physiculus dalwigki (Kaup, 1758) from the coast of Senegal is reported in this note. They were two adult specimens which measured 244 mm and 302 mm for total length, respectively, and weighed 81.8 g and 174.0 g, respectively. They were caught by trammel nets in the marine area of Dakar. They were described while mrophometric measurements and meristic counts were provided. These two findings constitute the first substantial records of P. dalwigki in the Senegalese waters, but also the southern extension range of the species from the western coast of Africa

Biologija reprodukcije Rhizoprionodon acutus (Rüppell, 1837)(Chondrichthyes: Carcharhinidae)u obalnom području Senegala (istočni dio tropskog Atlantika)

The milk shark, Rhizoprionodon acutus (Rüppel, 1837), is the shark species most abundantly landed at fishing sites along the Senegalese coast in the eastern tropical Atlantic. Adult males and females were mainly captured from March to September. The smallest adult male was 840 mm total length (TL) and weighed 2650 g; all males above 950 mm TL were adult. The smallest adult female was 890 mm TL and 4800 g; all females above 1000 mm were adult. The largest male and female were 1215 mm and 1260 mm TL and 6700 g and 6830 g, respectively. There was a significant difference in the total mass vs. TL relationship between males and females. Parturition and mating occurred in May and June. Gestation lasted approximately one year. Females had an annual reproductive cycle although some reproduced in alternate years. The diameter and mass of the largest yolked oocytes ranged 20-23 mm (mean 21.2±0.9) and 4.1-5.6 g (mean 4.8±0.5). Both uteri were compartmentalized into chambers with a single embryo in each chamber. Size and mass at birth, based on term embryos and neonates, ranged 325-500 mm TL (mean 391.4±24.4) and 127-350 g (mean 220.7±37.9). A chemical balance of development based on mean dry mass of the largest yolked oocytes and term embryos was 23. Ovarian fecundity was slightly higher than uterine fecundity. There was a slight positive relationship between uterine fecundity and female TL, but not between ovarian fecundity and female TL. Litter sizes ranged from one to eight (mean 3.5±1.3) with males and females equally distributed. In free-swimming specimens, females significantly outnumbered males, especially among sub-adult and adult specimens.Morski pas, Rhizoprionodon acutus (Rüppel, 1837), je najviše rasprostranjen na ribarskim postajama duž senegalske obale istočnog dijela tropskog Atlantika. Odrasli mužjaci i ženke su pretežito lovljeni od ožujka do rujna. Ukupna duljina (TL) najmanjeg primjerka mužjaka iznosila je 840 mm, a težina 2650 g, dok su svi odrasli mužjaci bili duži od 950 mm TL. Najmanja odrasla ženka bila je duga 890 mm TL i teška 4800 g, a sve odrasle ženke bile su duže od 1000 mm. Najveći primjerak mužjaka bio je dug 1215 mm i težak 6700 g, a najveći primjerak ženke bio je 1260 mm dug i 6830 g težak. Ustanovljena je statistički značajna razlika između odnosa mase i ukupne duljine (TL) kod mužjaka i ženki. Parenje i porod se odvijaju u svibnju i lipnju. Trudnoća je trajala oko godinu dana. Ženke su imale godišnji reproduktivni ciklus iako su se neke razmnožavale u naizmjeničnim godinama. Promjer najveće oocite sa žumanjcem iznosio je 20-23 mm (prosjek 21.2±0.9), a težina je kolebala između 4.1-5.6 g (prosjek 4.8±0.5). Oba uterusa bila su podijeljena u komorice i u svakoj od komorica razvijao se po jedan embrij. Dužina i težina kod rođenja, mjerena na embrijima i novorođenim primjercima procijenjene su na 325-500 mm TL (prosjek 391.4±24.4) i 127-350 g (prosjek 220.7±37.9). Kemijska ravnoteža razvoja, temeljena na prosječnoj suhoj težini najvećih oocita sa žumanjcem i embrijima bliskog vremenskog razdoblja, bila je 23. Ovarijska plodnost bila je veća od uterine plodnosti. Ustanovljen je pozitivni odnos između uterine plodnosti i ukupne duljine ženki, ali takav odnos nije ustanovljen kod ovarijske plodnosti i ukupne duljine (TL). Veličine izlegnutih mladih kolebale su od 1 do 8 (prosjek 3.5±1.3) podjednako kod mužjaka i ženki. Općenito je bilo više ženki nego mužjaka, naročito među slobodno plivajućim odraslim primjercima

Morphological abnormalities in the Striped panray, Zanobatus schoenleinii (Zanobatidae) from the coast of Senegal (Eastern Tropical Atlantic)

The capture of four abnormal specimens of the Striped panray, Zanobatus schoenleiniii was reported from shallow coastal waters surrounding the touristic area of Dakar, Republic of Senegal, and among them, some specimens displaying morphological deformities. A specimen exhibited a pectoral non-adherent to the head, a second was tailless, and two specimens displayed scoliosis at level of trunchal vertebrae and tail. The abnormalities are described and their causes and consequences herein considered.

First substantiated record of Cotton Mouth jack Uraspis secunda (Carangidae) from the coast of Senegal (E-Atlantic)

A specimen of Cottonmouth jack Uraspis secunda (Poey, 1860) was recorded for the first time from the coast of Senegal. The specimen was immature measuring 118 mm for total length and 19.2 g for total body weight. In this note, the authors present a short description of one specimen and its main morphometric measurements and meristic characters. The distribution of U. secunda in its new area of capture is commented and discussed, together with its close relative species U. helvola (Forster, 1801)

Aberrant hermaphroditism in striped panray, Zanobatus schoenleinii (Zanobatidae) from the coast of Senegal (e-tropical Atlantic)

A case of hermaphroditism is described in the present paper from a specimen of striped panray, Zanobatus schoenleiniii (Müller and Henle, 1841), captured off Dakar, Senegal, eastern tropical Atlantic. It measured 295 mm for disc width (DW), 530 mm for total length (TL) and its total body weight (TBW) reached 1017 g. It exhibited a single clasper, on the left side. Internally, the left genital apparatus was female, and the right male. It was an aberrant case of hermaphroditism due to the fact that lacking of clasper generally matches with a female genital apparatus. A relationship DW versus TWB expressed in logarithmic co-ordinates showed that the specimen developed in the wild similarly to normal specimens. The causes of this abnormality remain obscure but the role of pollutants in the local marine area cannot be totally ruled out

Socioeconomic performance of West African fleets that target Atlantic billfish

Managing marine resources is a contentious and complicated process. There are various users with competing objectives, especially in the case of artisanal and recreational fisheries management. Managers must consider not only the biological sustainability of the resources, but also account for the socioeconomic objectives of the fishery users, particularly in developing countries. In-person surveys were implemented with artisanal fishers that target billfish in Ghana and with recreational charter boat anglers that target billfish in Senegal. Data from the survey were used to compile financial performance indicators that describe the sustainability of the operations. In addition social and resource management perception data were collected in each location. The results of the study indicate that both fleets exhibit positive profit levels. Although fishers in both study locations perceived a declining billfish resource, they were largely unwilling to accept management measures to improve the resource. If management measures were to be considered for the artisanal fleet, managers should simultaneously introduce mechanisms to improve the technological storage capacity of harvested fish and training on saving schemes for artisanal fishers. Managers should also monitor the number of recreational vessels and their effort in Senegal. Performance indicators such as these are applicable and appropriate for quantitatively assessing the profitability of fishing fleets

O pojavi ribe Acanthurus monroviae Steindachner, 1876 (Osteichthyes: Acanthuridae) izvan obalih voda Alžira (južni Mediteran)

Two records of the Monrovian surgeonfish, Acanthurus monroviae Steindachner 1876, off the coast of Algeria (southern Mediterranean) are recorded for the first time. The species is briefly described and its distribution in the Mediterranean Sea is discussed.Autori izvješćuju o prvom nalazu dvaju primjeraka ribe Acanthurus monrovie Steindachner, 1876 izvan alžirskih obalnih voda (južni Mediteran). Dat je kratak opis tih primjeraka i raspodjela ove vrste u Mediteranu

Simple scaling of extreme precipitation regime in Senegal

Extreme precipitation exhibits high temporal and spatial variability, and understanding this variability is crucial for designing hydraulic infrastructures and assessing the impacts of natural risks such as floods and droughts. The Simple Scaling (SS) model, which describes the dependence of extreme rainfall statistics on timescales, is used to estimate Intensity Duration Frequency (IDF) curves. This study aims to evaluate the validity of the Simple Scaling (SS) hypothesis for 14 rain gauges in Senegal and explore the existence of breaks in temporal scaling regimes (transition regimes). For the analysis of extreme characteristics, we considered the Annual Maximum Series (AMS) of precipitation in sub-hourly and supra-daily durations ranging from 10 min to 7 days. The empirical validation of the SS models was confirmed for the majority of the scaling intervals. We identified two scaling breaks, indicating the presence of three scaling regimes: short durations (SD), intermediate durations (ID), and long durations (LD). The spatial variation of scaling exponents reveals the existence of different scaling regimes across Senegal. The results are valuable for modeling the spatial distribution of scaling exponents, which can aid in characterizing IDF curves at ungauged locations