New locations and parasitological findings for the invasive shrimp Palaemon macrodactylus in temperate southwestern Atlantic coastal waters

Abstract

This paper presents new records that considerably expand the geographical range of the invasive shrimp Palaemon macrodactylus in Argentina to include new estuarine areas on the Argentine south Atlantic coast: Bahía Samborombón, and the Bahía Blanca and Río Negro estuaries. The latter 2 locations are the southernmost reports for this species. The epibiotic barnacle Balanus amphitrite and a microphallid metacercaria Odhneria sp. are reported for the first time in P. macrodactylus. The prevalence of white spot syndrome virus (WSSV) was 10% in the Bahía Blanca estuary. Our results strongly suggest that WSSV is spreading in crustacean populations in the Argentine Sea and that P. macrodactylus plays a role in the ecology of parasite infections in this environment. MATERIALS AND METHODS Shrimp were sampled between March 2007 andMarch 2011 at 4 sites in Argentina: the Río Salado flood re lief channel (Site 1: 35°50' S, 57°25' W; n = 49) and Tapera de López (Site 2: 36°19' S, 56°46' W; n = 46) in Bahía Samborombón, the Bahía Blanca estuary (Site 3: 38°44' S, 62°22' W; n = 110), and the Río Negro estuary (Site 4: 41°1' S, 62°47' W; n = 1). The first 3 sites are located in the Buenos Aires province, and the fourth site is in the Río Negro province (Fig. 1). Specimens were collected using cast nets and minnow traps baited with fish meat. The specimens were transported alive to the laboratory and kept in small aquaria with seawater. Some ovigerous females were kept alive until their eggs hatched, and the resulting larvae were fixed in 10% formalin for morphological studies.The shrimp were studied alive, killed by freezing, and fixed in 10% formalin until examination for parasites using a stereomicroscope. A total of 20 specimens from Bahía Blanca estuary were examined fresh for the presence of white spots suggestive of WSSV. These specimens were then preserved in 96% ethanol and tested for WSSV using nested PCR. DNA was extracted from the gills using DNeasy kits (Quiagen). PCR amplification was conducted using illustra PuReTaq Ready-To-Go™ PCR Beads (GE Healthcare). Details of the primers and PCR procedures used are de scribed by Martorelli et al. (2010). Unless otherwise stated, throughout the present study, we refer to parasites and pathogens as simply 'parasites'.We deposited voucher specimens from each sampling area in the invertebrate collection of the La Plata Museum (voucher number): Río Salado (26753) and Tapera de López in Bahía Samborombón (26754), Bahía Blanca estuary (26755), and Río Negro estuary (26756). We also deposited one specimen with an epibiont from Tapera de López (26757) and zoea larvae from Bahía Blanca estuary (26758). RESULTSThe present paper presents the southernmost report of Palaemon macrodactylus off the southwestern Atlantic coast. We also report for the first time a helminth parasite and an epibiotic exotic crustacean in P. macrodactylus and provide new data on the prevalence of WSSV in P. macrodactylus from the Argentine Sea. P. macrodactylus individuals, including females bearing ...

Seasonal variation in reproductive traits of the oriental shrimp Palaemon macrodactylus (Crustacea: Caridea: Palaemonidae) in a non-native population

“…Although it is commonly associated with brackish water estuarine areas (Béguer et al 2011), the first record of the species in the southwestern Atlantic was from Mar del Plata harbor, Buenos Aires Province, Argentina (Spivak et al 2006), where fully marine conditions prevail. Recently, Martorelli et al (2012) discovered three new invaded sites in Argentinean coasts: Bahía Samborombón, Bahía Blanca, and the mouth of Río Negro, all of them estuarine environments.…”

Monitoreo del virus del síndrome de la mancha blanca (WSSV) en muestras de langostino (Pleoticus muelleri) durante los años 2010 a 2014 en la Argentina

“…Cabe considerar que en la metodología utilizada por Martorelli et al (2010) no está expuesto que se haya realizado ninguna verificación (secuenciación) de los productos obtenidos por PCR; la OIE afirma que cuando un resultado positivo por PCR de dos pasos no se puede confirmar como WSSV por secuenciación, se considerará negativo. Por lo expuesto y en concordancia con lo publicado por Costagliola et al (2013), la determinación informada por Martorelli et al (2010Martorelli et al ( , 2012 debería considerarse como un hallazgo no confirmado. Por otra parte, una publicación reciente del mismo autor menciona la ausencia del virus en un monitoreo durante los años 2010 a 2014 en crustáceos del estuario de Bahía Blanca (Martorelli et al 2017).…”

Screening for WSSV in crustacean from marine areas of Buenos Aires, Argentina

“…Sampling sites were chosen mainly considering the site where the virus was found in 2008-2009. In addition, in this study specimens of P. macrodactylus from Samborombon Bay were included, a new place reported for this alien shrimp (Martorelli et al 2012), and also specimens of Pleoticus muelleri from Mar del Plata because of the commercial importance of this crustacean in Argentina.…”