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Abstract

This study was designated to reveal reproduction aspects of D. neapolitana that can support the domestication and cultivation of D. neapolitana. This research method is a survey method, and sampling was carried out three times at four points in the mangrove area of Jeruklegi Cilacap. The samples that have been taken are taken to the Animal Physiology Laboratory and stored in a bucket of 15 ppm brackish water and then aerated. The variables measured were the number of worm segments, worm body weight, the sex ratio of the worms, the development of male and female gametes and environmental factors. To see the relationship between parameters, correlation analysis, regression and t-test were used to determine the difference in the number of segments and body weight of male and female worms. The sex ratio value obtained was 1: 1. The body size of the female and male D. neapolitana worms was not significantly different. Observations on female worms showed the number of segments means 131.96 ± 28.19 pieces; body weight means 2.65 ± 1.15 g and egg diameter mean 219.656 ± 9.75 µm. Male worms had several segments represent 136.97 ± 24.51; body weight means 2.18 ± 1.11 g and the form of sperm was tetrad spermatid. While indetermined worms had several segments mean 115 ± 39.38 and body weight mean 2 ± 0.73 g. The results of the analysis of the relationship between body weight and maturation level of D. neapolitana obtained the value of r = 0.009, linear regression equation y = 219868 -0.080x; and the value of t count (-0.043) <t table (2.07961) and the results of the analysis of the relationship between the number of segments and maturation level of D. neapolitana, the value of r = 0.101, linear regression equation y = 224,247-0.035x; and t count (-0.463) <t table (2.07961). Bodyweight did not have a positive correlation with the maturation level of D. neapolitana worms. Increasing body weight does not always follow by an increase in maturation, and increasing in several segments was not still followed by the rise in the maturation of D. neapolitana worms.

Sexual Maturity and Macronutrient Contents in Diopatra sp. (Onuphidae, Polychaeta) Maintained at Different Salinity Levels

“…The oocytes' shape was rounded, and the diameter of the oocytes in the sexually submature worms ranged between 200 and 210 μm with an average of 205.8 μm, whereas sexually mature worms had oocytes with a diameter ranging between 220 and 230 μm with an average of 225.4 μm (Figure 1A.). These findings are in agreement with the study of Purwati et al (2020) in which Diopatra worms collected from Cilacap showed different levels of sexual maturity based on the diameter of the oocytes. The oocyte diameters of the sexually submature and mature female worms were below 200 μm and 208-240 μm, respectively, and the cells did not appear to have nurse cells.…”

“…about 52% (Rachmad and Yuwono, 2000), and Jeruklegi, i.e. 60-66% (Wibowo et al, 2019) and 47-51% (Wibowo et al, 2020 a ). It was also lower than that of female epitokes of wawo worms (family Eunicidae) collected from Ambon, i.e.…”

“…nearly 30% (Rachmad and Yuwono, 2000), and Jeruklegi, i.e. 12-22% (Wibowo et al, 2020 a ), as well as the female epitokes of wawo worms, i.e. about 11% (Pamungkas, 2015).…”

“…The content was however higher than that of Nereis sp. studied by Wibowo et al (2019Wibowo et al ( , 2020 ), i.e. 14-22% and 1-10%, respectively, and the female epitokes of wawo worms, i.e.…”

“…In Cilacap, Central Java Province, Indonesia, Diopatra worms are also used as fishing bait by local anglers (Wibowo et al, 2022) the animals are called 'lur umah' in the local language, which means a worm with housing. The worms were initially identified as D. neapolitana by Purwati et al (2020), but the occurrence of this European species in Indonesian waters is highly unlikely considering the long distance between the two geographic regions. In such case, a detailed taxonomic work will reveal the identity of the species; for example, the worms D. neapolitana in Malaysia were later identified as D. claparedii by Idris and Arshad (2013).…”