scholarly journals Reproductive cycle of Bolinus brandaris (Gastropoda: Muricidae) in the Gulf of Gabès (southern Tunisia)

2013 ◽  
Vol 14 (1) ◽  
pp. 24 ◽  
Author(s):  
K. ELHASNI ◽  
P. VASCONCELOS ◽  
M. GHORBEL ◽  
O. JARBOUI
Keyword(s):  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Fishery Management ◽  
Gonadosomatic Index ◽  
Condition Index ◽  
Spawning Season ◽  
Gonad Maturation ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Bolinus Brandaris

The reproductive cycle of the purple dye murex (Bolinus brandaris) from the Gulf of Gabès was studied through gonad histology and calculation of bio-physiological indices (general condition index - K and gonadosomatic index - GSI). The shell length at first sexual maturity (SL50) of B. brandaris was also investigated using a macroscopic maturation scale. The population sex ratio was statistically unbalanced (M:F = 1:1.5), with a significant dominance of females. Monthly variation in gonad maturation stages, K and GSI revealed that B. brandaris has an annual reproductive cycle, long period of gonadal activity and slight asynchrony between sexes. The spawning season extended between April and July, with a clear spawning peak from May to June. The SL50 was reached at 56.4 mm in females and 54.6 mm in males. At present, B. brandaris has no commercial value in Tunisia, but it is predictable that it will become a fishery-exploited species in the near future. The present data, particularly the timing of spawning season and the size at first sexual maturity, constitute baseline information for the proposal of fishery management measures, aiming to ensure sustainable exploitation and long-term preservation of this alternative fishing resource.

Reproductive cycle and size at first sexual maturity ofHexaplex trunculus(Gastropoda: Muricidae) in the Gulf of Gabès (southern Tunisia)

2010 ◽  
Vol 54 (4) ◽  
pp. 213-225 ◽  
Author(s):  
KAMEL ELHASNI ◽  
MOHAMED GHORBEL ◽  
PAULO VASCONCELOS ◽  
OTHMAN JARBOUI
Keyword(s):  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Southern Tunisia

The reproductive cycle, condition index, and glycogen reserves of the cockles Cerastoderma glaucum from the Gulf of Gabès (Tunisia)

2015 ◽  
Vol 22 (22) ◽  
pp. 17317-17329 ◽  
Author(s):  
Sahar Karray ◽  
Wafa Smaoui-Damak ◽  
Tarek Rebai ◽  
Amel Hamza-Chaffai
Keyword(s):  
Reproductive Cycle ◽  
Condition Index ◽  
Gulf Of Gabes ◽  
Cerastoderma Glaucum ◽  
Gulf Of Gabès ◽  
Cycle Condition

Reproductive cycle of the Manila clam (Ruditapes philippinarum): an intensively harvested invasive species in the Tagus Estuary (Portugal)

2017 ◽  
Vol 98 (7) ◽  
pp. 1645-1657 ◽  
Author(s):  
Paula Moura ◽  
Paulo Vasconcelos ◽  
Fábio Pereira ◽  
Paula Chainho ◽  
José Lino Costa ◽  
...  
Keyword(s):  
Invasive Species ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Ruditapes Philippinarum ◽  
Manila Clam ◽  
Tagus Estuary ◽  
Gonad Maturation ◽  
Oocyte Diameter ◽  
Ruditapes Decussatus ◽  
Spawning Period

The present study aimed to describe the reproductive cycle and estimate the size at sexual maturity of the Manila clam (Ruditapes philippinarum) in the Tagus Estuary (Portugal). Specimens were collected monthly from September 2013 to December 2015 during fishing surveys using bivalve dredges. The gametogenic cycle was described in detail using gonad histology and monitored throughout the study period by the monthly variation in the frequency of gonad maturation stages, mean gonadal index and mean oocyte diameter. This invasive population of R. philippinarum displayed synchronous gonadal development between sexes, with ripening occurring mainly in April and May followed by an extensive spawning period until November–December. Individuals reached the size at first sexual maturity at 29.4 mm in shell length (i.e. before 1 year old). Furthermore, the reproductive strategy, dynamics and potential were compared between the invasive R. philippinarum and the native congeneric carpet shell clam (Ruditapes decussatus). Overall, the data gathered in this study constitutes valuable baseline information to propose conservation strategies and implement management measures to minimize the harmful impacts caused by this invasive species on local ecosystems and native biodiversity, particularly over populations of autochthonous bivalves.

scholarly journals Seasonal variations in the population biology of Salmostoma bacaila (Cyprinidae) from a tributary of the Payra River, Bangladesh

2019 ◽  
pp. 113-119
Author(s):  
Ahamed Ahamed ◽  
Faruque Ahmed Zoarder ◽  
Jun Ohtomi
Keyword(s):  
Sex Ratio ◽  
Seasonal Variations ◽  
Population Biology ◽  
Sexual Maturity ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Frequency Distributions ◽  
Size At Sexual Maturity ◽  
Management And Conservation

Some biological parameters of Salmostoma bacaila – including sex ratio, length-frequency distributions (LFDs), size at sexual maturity, spawning season, length-weight relationships (LWRs) and condition factor – were studied. Samples were collected seasonally during June 2017 to May 2018 from a tributary of the Payra River. The overall sex ratio was significantly different from the expected value of 1:1 (p < 0.001), in favour of male specimens. Females were significantly larger than males. Size at sexual maturity was estimated at 7.6~7.7 cm total length. Seasonal variations in the gonadosomatic index (GSI) indicate that the main spawning season is from spring to summer. The LWRs showed negative allometric growth in both sexes, but with clear seasonal variation. Fulton’s condition factor varied in both sexes and was attributed to variations in GSI with maturity. The fin¬dings of this study will be helpful for management and conservation of S. bacaila populations.

Reproductive cycle of Bolinus brandaris and penis and genital duct size variations in a population affected by imposex

2002 ◽  
Vol 82 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Montserrat Ramón ◽  
María José Amor
Keyword(s):  
Reproductive Cycle ◽  
Vas Deferens ◽  
Western Mediterranean ◽  
Spawning Season ◽  
Genital Duct ◽  
Penis Length ◽  
June July ◽  
A Site ◽  
Bolinus Brandaris

The reproductive cycle of Bolinus brandaris (Gastropoda: Muricidae) was investigated. Specimens were sampled monthly from a site off Sant Carles de la Ràpita, in the western Mediterranean, between February 1999 and March 2000. A pattern was observed in the reproductive cycle, with two reproductive peaks (April and June–July). The first stages of gametogenesis began in September for males and November for females. Mature males were found from December to April and from June to July. Maximum ripening in females was attained at the end of June and during July, coinciding with the spawning season. In May, there was a resting stage in females, and for both sexes from August to October.Males exhibited variation in penis length and vas deferens width related to the reproductive cycle. Sizes of both dimensions increased as maturation progressed. The variation was not found in imposex females.

Host switch and infestation by Ligula intestinalis L. in a silver bream (Blicca bjoerkna L.) population

Parasitology ◽  
2012 ◽  
Vol 139 (3) ◽  
pp. 406-417 ◽  
Author(s):  
M. VANACKER ◽  
G. MASSON ◽  
J-N. BEISEL
Keyword(s):  
Gonadosomatic Index ◽  
Rutilus Rutilus ◽  
Condition Index ◽  
Gonad Maturation ◽  
Host Switch ◽  
Ligula Intestinalis ◽  
Fat Reserves ◽  
Host Sex ◽  
Significant Difference ◽  
The Impact

SUMMARYSampling of the fish community was carried out for 20 years in the Mirgenbach reservoir, in North-Eastern France. The prevalence and the mean intensity of Ligula intestinalis (Cestoda) were analysed in roach (Rutilus rutilus) and silver bream (Blicca bjoerkna) populations, the main two infected species. The aim of this study was to investigate the host switch from roach to silver bream and the consequences of L. intestinalis infestation in silver bream, which is an unusual host for this parasite as Ligula parasitism in silver bream appears to be rare. We analysed in detail the relationships between parasitism index (PI), gonadosomatic index (GSI), perivisceral fat abundance (PFA) and condition index (CI) in the silver bream population. In 1998, prevalence of L. intestinalis highlighted a clear host switch from roach to silver bream. In the silver bream population, young fish were the most severely infected and the impact of plerocercoids appeared to be different depending on the host sex. In male silver bream, plerocercoids drew energy from fat reserves even if GSI was also slightly impacted. On the contrary, in females energy was diverted from gonad maturation rather than from perivisceral fat reserves. No significant difference was observed in terms of CI in either sex.

Sign in / Sign up

Export Citation Format

Share Document