Introduction

The genus Ficopomatus Southern, 1921 includes five species of brackish-water serpulids (ten Hove and Kupriyanova 2009): Ficopomatus macrodon Southern, 1921, from India and Sri Lanka (ten Hove and Weerdenburg 1978); Ficopomatus enigmaticus (Fauvel, 1923), recorded from subtropical-temperate waters worldwide (Fauvel 1923, ten Hove and Weerdenburg 1978); Ficopomatus miamiensis (Treadwell, 1934), widely distributed in the Gulf of Mexico and Caribbean (Rioja 1945, ten Hove and Weerdenburg 1978, Bastida-Zavala and Salazar-Vallejo 2000, and see below); Ficopomatus uschakovi (Pillai, 1960), from Indo-Pacific and West Africa (ten Hove and Weerdenburg 1978); and Ficopomatus talehsapensis Pillai, 2008, known only from Taléh Sap, Gulf of Thailand (Pillai 2008). It should be noted that we do not follow Pillai (2008), who reinstated the genus Neopomatus for the species uschakovi on the single autapomorphy of left and right thoracic membranes joined over the thorax.

On the Pacific Coast of America, no indigenous species of Ficopomatus has been described (Bastida-Zavala 2008). However, Ficopomatus enigmaticus, was recorded as an exotic species from San Francisco Bay, California (ten Hove and Weerdenburg 1978, Bastida-Zavala 2008), and, recently, Ficopomatus miamiensis was recorded from Urías lagoon, near Mazatlán, southeast of the Gulf of California, as an exotic species related to shrimp-ponds; however, the introduction could have taken place 20 years ago, when shrimp larvae were imported from Florida (Salgado-Barragán et al. 2004, Tovar-Hernández et al. 2009).

The case of Ficopomatus enigmaticus, a serpulid widely dispersed around the world and with a long historical record of invasions, is a well-known example, because it can have dramatic impacts in invaded habitats building large, reef-like colonies in some coastal lagoons that cause major changes in benthic communities, especially in the Lake of Tunis (ten Hove and van den Hurk 1993) and the Mar Chiquita Lagoon, Argentina (Schwindt et al. 2001, Luppi and Bas 2002, Bazterrica et al. 2012). Rioja (1943) recorded, for the first time, Ficopomatus enigmaticus from Puerto Quequén, south of Mar del Plata, and now the species is widely distributed in the Mar Chiquita Lagoon, forming annular reefs and having several effects on the ecosystem and navigation of fishing boats in this lagoon-system (Schwindt et al. 2001, Luppi and Bas 2002, Schwindt et al. 2004a, b). Borthagaray et al. (2006) analysed the potential impacts of this invasive species in other lagoons of La Plata River, especially of the Uruguay coast.

The effects of Ficopomatus miamiensis in Urías lagoon were considered to be positive in the shrimp-ponds because the population of these serpulids (densities higher than 230, 000 ind/m²) helps to clean the water and control the suspended particulates. However, the impact of the colonies attached to the mangrove roots is negative, because the serpulid competes with other fouling and filter-feeding invertebrates such as native barnacles, mussels and oysters (Tovar-Hernández et al. 2009).

Ficopomatus uschakovi has been recorded from the Gulf of Guinea, West Africa since the 1950’s (Hartmann-Schröder 1971). Recently, this species was recorded in north-eastern Brazil (de Assis et al. 2008) and Venezuela (Liñero-Arana and Díaz-Díaz 2012).

Materials and methods

From 19–24 September, 2011, we visited several sites to collect marine invertebrates in Chiapas, including Puerto Chiapas (or Puerto Madero, as its old name), La Encrucijada Biosphere Reserve, Chocohuital, Boca del Cielo Lagoon, Paredón (Mar Muerto Lagoon) and ending in Oaxaca, in San Dionisio del Mar (Superior Lagoon). Serpulid samples were taken from hard substrates such as rocks, mangrove roots and artificial structures (e.g. piers, submerged buildings, etc.). The preliminary examination of the specimens included only the samples from La Encrucijada Biosphere Reserve because Ficopomatus tubes were immediately identified in the field. In the other sites in Chiapas and Oaxaca the typical tubes of Ficopomatus were not found. Most specimen lots were deposited in the Colección de Invertebrados Marinos, Universidad del Mar, Puerto Ángel, Oaxaca (UMAR-Poly), other samples were deposited in the collections of El Colegio de la Frontera Sur, Chetumal, Quintana Roo (ECOSUR), and in the Universidad Autónoma de Nuevo León, Monterrey, México (UANL). Topotypical specimens examined came from the Los Angeles County Museum of Natural History, Allan Hancock Foundation, Los Angeles, California, USA (LACM-AHF).

The specimens were fixed with 10% formalin and preserved in 70% alcohol. The line drawings were made using camera lucida, the photographs were taken with a digital camera (Nikon Coolpix). Opercula were generally found to be covered in silt and algae, and were, therefore, cleaned with a fine brush.

Standard measurements and counts were total length, measured from the most distal part of the operculum to the pygidium; thoracic length, from the apron to the base of the collar; thoracic width, measured across the collar region; the number of thoracic chaetigers, the number of radioles in each lobe of the branchial crown; opercular length, from the base of peduncle to the end plate; and opercular diameter, measured across the dorso-ventral axis of the end plate.

The abbreviations used in the text were as follows: OL (opercular length), OD (opercular diameter), THL (thoracic length), THW (thoracic width), TL (total length of the body), n (sample size), r (range of data), µ (mean), and ± (standard deviation).

Systematics Class Polychaeta Grube, 1850 Family Serpulidae Rafinesque, 1815 Genus Ficopomatus Southern, 1921

Type species. Ficopomatus macrodon Southern, 1921 by monotypy.

Discussion

The presence of a species, resembling Ficopomatus uschakovi, from La Encrucijada Biosphere Reserve was initially brought to the attention of the authors two years ago (S.I. Salazar-Vallejo et al. pers. comm. 2009). Previously, no other record of the species existed throughout the Tropical Eastern Pacific. However, the observations in the field show that Ficopomatus uschakovi is widely distributed in La Encrucijada, suggesting that the invasion event of this species may have occurred several years ago.

Although ballast water, sediment transport and fouling are the main means of dispersal of aquatic exotic species (Carlton and Geller 1993, Ruiz et al. 2000, Okolodkov et al. 2007), the means of dispersal of Ficopomatus uschakovi in La Encrucijada Biosphere Reserve still remains unclear, as the nearest port (Puerto Chiapas) is 70 km to the south, and there are no port installations or any shrimp cultures in the lagoon. The local people mentioned that these serpulids had gone unnoticed until now and apparently negative effects to the ecosystem have not been detected, except the fouling of the fishing boats, which require frequent cleaning.

Mass occurrence of Ficopomatus uschakovi was observed (Fig. 2A), however, not to the extent of the reef-like structures, formed by Ficopomatus enigmaticus in Argentina (Schwindt et al. 2004a, b) and by Ficopomatus miamiensis in Mazatlán (Tovar-Hernández et al. 2009). However, similar impacts as caused by the latter species may be expected for Ficopomatus uschakovi. Therefore, it is necessary to conduct detailed monitoring of Ficopomatus uschakovi in the sites that have been invaded. It is also recommend that an exhaustive study in the coastal lagoons of Chiapas be conducted to evaluate the real distribution and the impact generated by Ficopomatus uschakovi.