Larval development of the shrimp Hippolyte sapphica d’Udekem d’Acoz, 1993 forma A and B (Decapoda: Caridea: Hippolytidae) reared in the laboratory, confirmation of the conspecific status of the two forms

Abstract

The complete series of larval staging of Hippolyte sapphica d’Udekem d’Acoz, 1993 forma A and B from Louros estuary was studied in the laboratory and described in detail for the first time. The reared larvae of H. sapphica passed through six zoeal stages and one megalopal stage. The larval monitoring completed when the individuals could be assigned clearly to form A and B via rostra formation. Under the experimental conditions, the average durations of the larval stages were as follows: three days for 1 st and 2 nd stages, three to four days for 3 rd , 4 th , 5 th and 6 th stages, four days for the megalopal stage and 19 to 30 days for immature form A and B individuals. Comparison of the larval morphological characters among the described material and the bibliographic data of closely related species was made and discussed. The offspring of females of the forma A includes forma A and B and the same can be said of the offspring of the forma B. This confirms that the formae A and B are indeed conspecific.

Global biogeography, cryptic species and systematic issues in the shrimp genus Hippolyte Leach, 1814 (Decapoda: Caridea: Hippolytidae) by multimarker analyses

“…This species inhabits shallow seagrass meadows in the central and eastern Mediterranean 2 , 44 , although forma B has only been reported from the Amvrakikos Gulf (Greece) and Venice Lagoon (Italy), always sympatric with forma A 45 . Larval development studies of both forms concluded that females of both forms can generate larvae ultimately developing in adults of either form 46 . The present phylogenetic analysis indeed corroborates that these forms belong to the same species with negligible differences in their genetic makeup.…”

How a sharp rostral dimorphism affects the life history, population structure and adaptability of a small shrimp: the case study of Hippolyte sapphica

“…This holds for the sexually differentiated specimens, as the form differentiation always precedes the sexual one (Ntakis et al . ), as well as for the juveniles, whose CL at the time of sacrifice was in the range 1.3–1.5 mm. At this size, no sign of transition from the short to the long rostrum type was observed anymore either in cultured or in wild individuals (Fig.…”

“…Based on the lack of other morphological differences, as well as on the same microdistribution over the habitat, d'Udekem d'Acoz () hypothesised that the two forms are conspecific, a hypothesis that has recently been confirmed (Ntakis et al . ).…”

“…Form B has been reported only from the Amvrakikos Gulf and the Venice Lagoon, although always as sympatric with form A. Based on the lack of other morphological differences, as well as on the same microdistribution over the habitat, d'Udekem d'Acoz (1996) hypothesised that the two forms are conspecific, a hypothesis that has recently been confirmed (Ntakis et al 2010).…”

“…1). Divergence between the two phenotypes becomes obvious soon after the completion of larval development but before the appearance of sexual appendages (d'Udekem d'Acoz 1993, 1996Ntakis et al 2010). Form B has been reported only from the Amvrakikos Gulf and the Venice Lagoon, although always as sympatric with form A.…”