Sclerozoan and fouling sabellid worms (Annelida: Sabellidae) from Mexico with the establishment of two new species

Abstract

The sabellid genera Anamobaea Krøyer, 1856 and Notaulax Tauber, 1879 are two of the most attractive polychaete worms in coral reefs. Anamobaea is represented by two Caribbean species and Notaulax with 24 species from around the world, six of them previously known to tropical America. During examination of fouling biota and sclerozoans from Mexico, Anamobaea orstedii Krøyer, 1856 was found in coral reefs from the southern Gulf of Mexico and three species of Notaulax were identified to the Mexican Pacific, two of them being new species to science. Anamobaea orstedii Krøyer, 1856 is first reported as sclerozoan of dead coral from the southern Gulf of Mexico. An amendment to the generic diagnosis of Anamobaea is provided, based on the presence of a higher number of skeletal cells than previously recorded; height, shape and exposition of the anterior peristomial ring; the non-fusion of dorsal collar margins to faecal groove; shape of collar chaetiger and abdominal chaetae and distribution and shape of radiolar ocelli. Notaulax californica (Treadwell, 1906) is reported as fouling in buoys and docks from the Gulf of California. Two new species of Notaulax are described: the former was found in hull and dock fouling from La Paz (Gulf of California) and the second one as sclerozoan of oysters from a dock fouling in Acapulco (south Mexican Pacific). In addition, reproductive features are described for the first time for A. orstedii which is a simultaneous hermaphrodite with female and males gametes found within the same segments of abdominal region. Oocytes develop synchronously and sperm morphology (spherical nucleus and rounded acrosome, four spherical mitochondria and a long free flagellum) suggest an adaptation to broadcast spawning and external fertilisation. Species of Notaulax here examined were gonochoric, with gametes distributed in abdominal segments.

Morphological Modifications and Injuries of Corals Caused by Symbiotic Feather Duster Worms (Sabellidae) in the Caribbean

“…The symbiotic worms, identified as split-crown feather duster worms of the genus Anamobaea Krøyer, 1856 [22,27,29], showed some variation in coloration, ranging from white to dark red and various combination patterns of these colors (Figures 2, 3 and 9A). Two species from the Caribbean have been described, which can be distinguished by two morphological characters [27,29,32] that are not clearly visible in the photographs: Anamobaea phyllisae Tovar-Hernández & Salazar-Vallejo, 2006 has two dorsal kidney-shaped shields over the anterior margin of the base of its crown and smooth flanges (without papillae) and Anamobaea orstedi Krøyer, 1856 does not have such shields, and its flanges are wrinkled (with papillae). The former species has so far only been reported from the type locality in the British Virgin Islands, whereas the latter has a wider geographic range [29,32].…”

“…Two species from the Caribbean have been described, which can be distinguished by two morphological characters [27,29,32] that are not clearly visible in the photographs: Anamobaea phyllisae Tovar-Hernández & Salazar-Vallejo, 2006 has two dorsal kidney-shaped shields over the anterior margin of the base of its crown and smooth flanges (without papillae) and Anamobaea orstedi Krøyer, 1856 does not have such shields, and its flanges are wrinkled (with papillae). The former species has so far only been reported from the type locality in the British Virgin Islands, whereas the latter has a wider geographic range [29,32]. Because we are not sure about the identity of the associated worms, we refer to them as Anamobaea sp.…”

“…Morphological anomalies are not exceptional among corals inhabited by associated fauna. For example, the sabellid Perkinsiana anodina lives in short tube-shaped protuberances on the surface of an encrusting mushroom coral, which are part of the host's coral skeleton [32,51]. Coral gall crabs have received much attention because of the crescent-, canopy, slit-, and basket-shaped pits inside various coral species [44,[56][57][58][59].…”

“…Although various sabellid species have been reported to live in coral reefs or more specifically on dead coral [25][26][27][28][29][30][31][32], they have received little or no attention in the literature about coral-associated fauna [8,[33][34][35][36][37][38][39][40][41][42][43][44][45] and symbiotic polychaetes [46][47][48], in contrast with serpulid worms. Only a few publications mention the identity of sabellid worms and their host coral species, such as the sabellids Amphicorina schlenzae Nogueira & Amaral, 2000 and Pseudobranchiomma minima Nogueira & Knight-Jones, 2002 in living colonies of the Brazilian endemic scleractinian Mussimilia hispida (Verrill, 1901) [49,50].…”

“…Only a few publications mention the identity of sabellid worms and their host coral species, such as the sabellids Amphicorina schlenzae Nogueira & Amaral, 2000 and Pseudobranchiomma minima Nogueira & Knight-Jones, 2002 in living colonies of the Brazilian endemic scleractinian Mussimilia hispida (Verrill, 1901) [49,50]. Furthermore, there are records from Indonesia of Perkinsiana anodina Capa, 2007 in an encrusting mushroom coral Cycloseris explanulata (van der Horst, 1922), misidentified as C. wellsi (Veron & Pichon, 1980) [51,52], and Notaulax montiporicola Tovar-Hernández & ten Hove, 2020, associated with the foliaceous coral Montipora nodosa (Dana, 1846) [24,32,51]. Finally, the fan worm Notaulax yamasui Nishi et al, 2017 was recorded from dead and living Porites sp.…”