Rare sexual anomalies in Temora stylifera (Dana, 1849) (Copepoda: Calanoida)

Abstract

sexual characters such as A1 and fifth leg (P5) were typically male ( Figure 2); and 2) Male bearing geniculation in both antennules:the specimen was observed alive in microcosms and displayed similar swimming behavior when compared to normal males. This animal did not show any other morphological abnormalities in addition to the double geniculation of A1 (Figure 1). The antennules were symmetrical, showing an identical number of segments, geniculation pattern and size. The configuration of the setae and modified segments follows that described by Corni et al. (2001) for both specimens. The gynandromorphic individual anomaly was not induced by parasites since detailed examination showed

Occurrence of a tumour-like abnormality in the telson skeleton of the brine shrimp Artemia (Branchiopoda, Anostraca)

“…The existence of morphological abnormalities in crustaceans has been recorded at irregular intervals and those reported include skeletal malformations (Pan-dourski & Evtimova, 2005), abnormalities in sexual characters (Brylinski, 1984;Martinelli-Filho et al, 2009;Long et al, 2010;Asem & Sun, 2013), and tumourlike anomalies (Skovgaard, 2004;Bhandare & Ingole, 2008). These malformations have been observed in the species' natural habitats as well as in laboratory studies (McKenney, 2005;Asem & Sun, 2013;Zambrano, 2017).…”

New non-sexual skeletal abnormalities in Acartia lilljeborgii Giesbrecht, 1889 (Copepoda, Calanoida)

“…Morphological abnormalities in copepods and other planktonic crustaceans are usually associated with tumour-like structures (Skovgaard, 2004;Bhandare & Ingole, 2008), sexual characters (Steuer, 1932;Brylinski, 1984;Martinelli-Filho et al, 2009;Long et al, 2010), and skeletal malformations (Pandourski & Evtimova, 2005). Pollution, ecto-and endoparasitism, and even food limitation have often been considered causes for these aberrations (e.g., Bowman, 1963;Behrends et al, 1997;Gusmão & McKinnon, 2009).…”