Mediomastus californiensis Hartman, 1944

Ribeiro, Rannyele Passos, Alves, Paulo Ricardo, Almeida, Zafira da Silva de & Ruta, Christine, 2018, A new species of Paraonis and an annotated checklist of polychaetes from mangroves of the Brazilian Amazon Coast (Annelida, Paraonidae), ZooKeys 740, pp. 1-34 : 19

Mediomastus californiensis Hartman, 1944 Fig. 11D

Type locality.

Tomales Bay, California (38°18'N, 122°56'W; estimated geolocation).

Material examined.

São Luís, 02°35'56"S, 44°21'11.8"W: two specimens, 21 October 2010 (NPM-Pol 73); three specimens, 18 August 2010 (NPM-Pol 858); one specimen, 18 March 2012 (NPM-Pol 859). Caranguejos Island, 02°49'33.6"S, 44°28'51.1"W: one specimen, 22 April 2010 (NPM-Pol 860), three specimens, 26 January 2011 (NPM-Pol 861); three specimens, 28 March 2011 (NPM-Pol 862); eight specimens, 28 March 2011 (NPM-Pol 863); one specimen, 17 December 2011 (NPM-Pol 864); four specimens, 2 July 2012 (NPM-Pol 865). Complete and incomplete specimens.

Distribution.

Pacific Ocean: Australia, USA, Mexico. Atlantic Ocean: Caribbean Sea, Brazil (states of Pará, Maranhão, Rio de Janeiro, São Paulo, Paraná and Santa Catarina, see Suppl. material 1).

Remarks.

First record for Maranhão. The specimens examined in this study have triangular prostomium with cylindrical palpodium, in dorsal view; peristomium devoid of setae with a pair of ocelli; 10 chaetigers in thoracic region; only capillaries in chaetigers 1-4; abdominal chaetigers only with hooded hooks defining them as Mediomastus californiensis (Hartman, 1944). In the present study, we found specimens exceeding 100 segments as observed by Warren et al. (1994). Although M. californiensis has been recorded in the Pacific (USA) and Atlantic Ocean (Canada and the USA), Warren et al. (1994) examined specimens from both oceans and did not observe differences among them. This species has been recorded in muddy bottoms of estuarine environments in the Brazilian Amazon Coast ( Rosa-Filho et al. 2006) and in the Caribbean Sea ( Gobin 1990).