Reproductive stages of the Ponto-Caspian amphipod, Pontogammarus maeoticus (Sowinsky, 1894) (Amphipoda, Pontogammaridae)

Abstract

The series of reproductive events in various species of Gammaridae can be described as precopula, copula, egg deposition and fertilization, hatching of the newborn, and the presence of young individuals. The stages of Pontogammarus maeoticus were explored in the laboratory. Amphipod samples were collected on the southwestern coast of the Caspian Sea (Jefrood Beach). The animals were transferred to the laboratory along with sediment from their habitat. The samples were maintained under controlled laboratory conditions at a temperature of 25 ± 1°C, a salinity of 9 ± 0.5‰ and in a 12 : 12 h light/dark regime for about six weeks. In this study, we examined the species’ reproductive sequence. The average time spent in the precopula stage was approx. 2.6 ± 0.91 days and embryonic development took about 8.5 ± 1.1 days. Fecundity was estimated as the number of fertilized eggs existing in the brood pouch of each female (average 14.12). The average length of females was recorded as 12.21 mm. The first precopula was observed about 40 days after hatching. The species has a relatively short reproductive cycle and the generations are able to reproduce after a short period (about 40 days). Hence, this species seems to be a good choice for potential use in aquaculture.

Are Ponto‐Caspian species able to cross salinity barriers? A case study of the gammaridPontogammarus maeoticus

“…In the Caspian Sea, P. maeoticus occurs in salinity ranging from 0 PSU to 18 PSU (Nazarhaghighi et al., ). However, the population selected to lower salinity in this study had still relatively high mortality in freshwater conditions, although we believe that further selection steps would result in possible adaptation to fresh water.…”

“…From the laboratory population reared at 10 PSU, 15–20 adults and 20–40 juveniles were transferred without acclimatization to each of the thirteen 56 L tanks (i.e., five tanks of 4 PSU, five tanks of 16 PSU, and three tanks of 10 PSU, respectively). Selection was conducted for 15 weeks corresponding to approximately 1–2 generations (Nazarhaghighi et al., ). Animals were reared under the above‐mentioned laboratory conditions, except that salinity was varied, and fed ad libitum with a mixture of fish food flakes, pellets, and green algae.…”

“…P . maeoticus has been chosen due to its euryhalinity, invasion record of inland waterbodies and reservoirs of Ukraine and Turkey (Alexandrov et al., ; Kocataş, Katagan, Özbek, & Sezgin, ; Özbek, ), wide spread distribution and high abundance in its native region (Mirzajani, ; Mordukhai‐Boltovskoi, ), and consecutive breeding and short generation time (1–2 months; Nazarhaghighi, Shabanipour, Zarghami, & Etemadi‐Deylami, ). During the experiments, we followed mortality of adults, hatching success, and growth and survival of offspring in different salinities.…”

Are juveniles as tolerant to salinity stress as adults? A case study of Northern European, Ponto‐Caspian and North American species

“…The differences in hatching success among species may be related to their different reproductive strategies. Gammarus salinus produces three to seven broods per generation with approximately 30 juveniles per brood, P. maeoticus only three broods with approximately nine juveniles per brood, while G. tigrinus produces at least ten broods with ten to 50 juveniles per brood (Nazarhaghighi, Shabanipour, Zarghami, & Etemadi‐Deylami, 2013; Sutcliffe, 1993 and references therein). Furthermore, in our study juveniles of G. salinus and G. tigrinus hatched in much wider ranges of salinities than those of P. maeoticus .…”

First report on the life history of the marine amphipod Ceradocus mizani and its implication for aquaculture

“…Amphipods are sensitive to a wide range of environmental disturbances, are ecologically relevant, and are amenable for experimentation in ecological and ecotoxicological studies, as has been demonstrated in the monitoring of Tributyltin, heavy metals, and organic pollution (Conlan, 1994; DeWitt et al, 1992; Guerra‐García et al, 2016; Nazarhaghighi et al, 2013; Neuparth et al, 2002). Amphipods are also a good model for proteogenomic, transcriptomic, and mitogenomic studies (Guerra‐García, 2019).…”