Reproductive seasonality and the gonadal maturation of silver pomfret Pampus argenteus in the Bay of Bengal, Bangladesh

Abstract

The silver pomfret (Pampus argenteus) is one of the most commercially important marine fish species in the Bay of Bengal, Indian Ocean. However, detailed information on the reproductive biology of silver pomfret is limited for the Bay of Bengal, Bangladesh. To understand their reproductive biology, especially the gonadal developmental cycle and spawning season, a total of 373 individuals were collected monthly from February 2016 to January 2018 and examined. The total length (TL) and weight (TW) of P. argenteus ranged from 18.82–35.73 cm and 89.26–617.60 g, respectively. The highest gonadosomatic index (GSI) values were observed from April–June with a second (smaller) peak in October. The highest oocyte diameter was observed in May (630.50 ± 96.70 μm), when the fish reached full maturity, and the lowest was observed in July (35.10 ± 7.12 μm), when new eggs began their development for the next spawning season. The maximum number of eggs in the ovary were found in the yolk granule stage in May with a number of post-ovulatory follicles, which indicated that the ovaries developed to a peak leading up to the spawning season. A number of spermatids were also seen in males in April–June along with females. From these detailed observations, it may be concluded that P. argenteus shows two spawning peaks, in May–June and October. This observation will be helpful for the artificial breeding, sustainable management and conservation of this species in the study area.

Estimation of population structure, growth and condition of Parastromateus niger in the Bay of Bengal

“…But the previous study recorded the maximum value of TL as 54 cm from the Bay of Bengal that was much higher than our recorded value (Karim et al 2020). Another study found the value of TL as 30.9 cm from the Bay of Bengal (Cox's Bazar) which was lower than our finding (Akhter et al 2020). This maximum length (38 cm) was also smaller than the fish of 56.2 cm caught from the Persian Gulf (Sahraei et al 2018) and 45 cm from the Indonesian coast (Damora et al 2018).…”

“…This study showed the isometric growth pattern of P. niger where the b value was close to 3 (b = 2.981), which indicates that the length increases proportionally with the body weight and this trend of proportional growth continues throughout the life. Both Akhter et al (2020) and Karim et al (2020) found negative allometric growth for this pomfret fish in the Bay of Bengal, where the values of b were less than 3. The fish also showed negative allometric growth (b < 3) in the Kuwait coast of the Arabian Gulf (Dadzie et al 2008).…”

“…Larger or smaller b value than 3 indicates positive (fish become weighty as length increases) or negative (fish grow more in length than weight) allometric growth as it will grow differently in three dimensions (Ricker 1973;Wootton 1998;Gayanilo et al 2003). Several studies were also performed on condition factors of other pomfret species and two pomfret species Chinese pomfret (P. chinensis) and silver pomfret (P. argenteus) had negative allometric growth (Dadzie et al 2008;Akhter et al 2020;Karim et al 2020). Additionally, the length-weight relationship (LWR) between TL and BW was found highly correlated as the value of r² was 0.951 for P. niger which matched with the previous studies (Dadzie et al 2008;Akhter et al 2020;Karim et al 2020).…”

Availability of Marine Fishes in Cox’s Bazar, Bangladesh: A Case Study on the BFDC Landing Center

“…Pampus argenteus and Euthynnus affinis) was higher during the winter, which might be due to their breeding season. The availability of rupchanda Pampus argenteus, for instance, was observed throughout the year, with two breeding periods during April and October (Akhter et al, 2020). Although the availability of medium-sized hilsa Tenualosa ilisha was observed during the winter, the standard size of hilsa was usually observed during the monsoon season (September-October) because of their breeding season (Rahman et al, 2012).…”

The ultrastructure of spermatogenic cells and morphological evaluation of testicular development in the silver pomfret (Pampus argenteus)

“…Besides, the males mature earlier than females, and two peaks of gonad maturation were observed in Kuwait, one in March-May and the other during August-September, in both males and females (Almatar et al, 2004;Lone et al, 2008a). In the East China Sea and India, the spawning peaks were from May to July and October (Akhter et al, 2020). Although the morphology of the testicular development process during the spawning period and mature sperm has been described in pomfret (Lone et al, 2008b;Zhao et al, 2010), there are no detailed descriptions of the testicular parameters, particularly the ultrastructure related to spermatogenesis in cultured pomfret.…”