New species of Eirenidae (Hydrozoa: Leptothecata) from the Amazonian coast (northern Brazil)

Everton Giachini Tosetto,Miodeli Nogueira Júnior,Sigrid Neumann-Leitão

doi:10.3989/scimar.05051.14a

Everton Giachini Tosetto, Miodeli Nogueira Júnior + Show 1 more

Open Access

https://doi.org/10.3989/scimar.05051.14a

Copy DOI

Abstract

Two new Eirenidae medusae species were collected on the Amazonian coast, Eutima marajoara n. sp. and Helgicirrha angelicae n. sp. The former differs from other species of the genus by the gonads extending along almost the entire length of the subumbrellar portion of the radial canals but not connected to the ring canal, up to 40 marginal tentacles with conical bulbs and 48 marginal warts, lateral cirri and adaxial papillae on some marginal warts and tentacular bulbs. Helgicirrha angelicae n. sp. differs from other species of the genus by the gonads on the middle portion of the radial canals with medusa buds, the short gastric peduncle, up to 20 marginal tentacles, some with adaxial papillae, up to three marginal warts and two statocysts between successive tentacles, and lateral cirri both on tentacle bulbs and marginal warts.

Highlights

Hydromedusae from the family Eirenidae Haeckel, 1879 are distinguished from other Leptothecata by the presence of a distinct gastric peduncle and closed statocysts (Bouillon et al 2006)
Genera of the family Eirenidae are mainly distinguished by the number of statocysts, the position of the gonads and the presence of marginal structures such as, cirri, warts and adaxial papillae (Bouillon et al 2006)
Ratios between tentacles and warts were not significantly correlated with umbrella diameter

Summary

Introduction

Hydromedusae from the family Eirenidae Haeckel, 1879 are distinguished from other Leptothecata by the presence of a distinct gastric peduncle and closed statocysts (Bouillon et al 2006). Eirenidae genera there are eight statocysts (rarely 12) while in others there are an indefinite number, but always more than eight in adult medusae (Bouillon 1984, 1999, Bouillon et al 2006). Among those with eight statocysts, Eutima McCrady, 1859 differs from Eugymnanthea Palombi, 1936 by the adult medusae.

Objectives

Findings

Discussion

Conclusion