First record of Thysanozoon brocchii (Platyhelminthes: Polycladida) from Indian waters

Abstract

This work reports the occurrence of Thysanozoon brocchii from the rocky intertidal coast of Ratnagiri and Dwarka, the West Coast of India, for the first time. Two morphotypes were found, the first morph has a buff brownish papillate dorsal surface, with few specimens having white spots. The second morph has light coloured papillae which form a distinct cross marking along the dorsal surface. The species possesses double male copulatory apparatus with seminal vesicle, prostatic vesicle and sclerotized stylet. This cosmopolitan species has previously been recorded from Italy and Mediterranean, Japan, South and West Africa, Florida, New Zealand, Brazil, and United Kingdom. Synonymized species and older descriptions have been compared to examine similarities and dissimilarities. Considering the existence of varied colour morphs of this species, a detailed comparative analysis of morphological characters, reproductive histology and molecular framework is recommended.

Two new Pseudoceros (Platyhelminthes: Polycladida: Pseudocerotidae) from Agatti Island, India and a species checklist from Indian waters

“…However, many works were published on polyclads during this period from nearby geographic areas in Arabian Sea such as Sri Lanka (Kelaart, 1858; Laidlaw, 1904), Maldives (Laidlaw, 1902, 1903), Djibouti (Mexiner, 1907 a , 1907 b ) and the Red Sea (Meyer, 1922; Prudhoe, 1952). Since 2011, efforts from a handful of researchers raised the number of species from nine to 68 from Indian waters (Apte & Pitale, 2011; Sreeraj & Raghunathan, 2011, 2013, 2015; Dixit & Raghunathan, 2013; Pitale et al ., 2014; Sreeraj et al ., 2015; Dixit et al ., 2015, 2017 a , 2017 b , 2018 a , 2018 b , 2018 c , 2019, 2021; Pitale & Apte, 2017, 2019; Dixit, 2018; present study). All species of polyclads reported from Indian waters are compiled in a checklist (Table 1) based on published reports.…”

New records of rarely reported species in the Mediterranean Sea (March 2024)

“…Thysanozoon brocchii is a cosmopolitan species reported in the Mediterranean Sea, the Atlantic, Pacific and Indian Oceans in a variety of habitats (Cuadrado et al, 2017;Pitale & Apte, 2017). In November 2022, four individuals of T. brocchii were recorded during a SCU-BA diving survey in a semi-submerged cave within the National Marine Park of Zakynthos Island, Ionian Sea, Greece (37.6614 o N, 20.8586 o E).…”

“…Originally described as a molluscan species (Tergipes brocchi Risso, 1818), this flatworm has about twenty synonyms previously given to different species (Pitale & Apte, 2017). It remains unknown whether the same species presents polymorphism across the world or if there are different closely related synonymised species.…”

“…It remains unknown whether the same species presents polymorphism across the world or if there are different closely related synonymised species. In this context, revision of this species is required based on molecular data and reproductive anatomy (Pitale & Apte, 2017).…”