First record of albinism in a tropical anguillid eel Anguilla bengalensis bengalensis from Malaysia

Abstract

This study reports the first occurrence of partial albinism in a tropical anguillid eelAnguilla bengalensis bengalensisfrom Malaysia. This paper also describes the first record of albinism in the genusAnguilla. The occurrence of albinism in our specimen ofAnguillamight have been caused by three factors: (1) contamination effects; (2) random genetic alterations; or (3) genetic alteration due to small population size. The present results suggest that the albinism inA. bengalensis bengalensisis probably caused by random genetic alteration. Partial albinism may not be a handicap in the life of the present specimen because the eel could still potentially grow to more than 1 m in total length, just like a normal adult eel.

Untitled

“…It has been reported in different studies that various factors like contaminated environmental parameters, light intensity, types of feeding during larval stages, endocrine hormones are responsible for body colour patterns and genetic factors including random genetic alteration, genetic alteration due to small population size are considered to cause colour abnormality in fishes (Tokac, Akyol, Aydin, & Ulas, 2013;Kadir et al, 2015). However, with respect to the location of the specimen caught, factors like heavy metals contamination in water and light intensity could be potentially excluded from the probable factors to cause colour change, because the open ocean is not generally contaminated and the species is a pelagic fish, thus light may not be an issue.…”

“…Albinism is a genetically inherited condition produced by an autosomal recessive gene in the homozygous state in which the pigmentation protein melanin is either absent or non functional (Westerman & Birge, 1978;Reum, Paulsen, Pietsch, & Parker-Stetter, 2008;Kadir, Rasid, Wong, & Kwong, 2015). There are two kinds of albinism widely reported in fishes, complete albinism that refers to total absence of integumentary and retinal pigmentation and another is partial albinism or leucism, which is characterised by complete or partial loss of integumentary pigments, but with retinal pigments present (Goto, Sato-Matsumura, Sawamura, Yolota, Nakamura, & Shimiz, 2004).…”

Validation of occurrence of tropical shads, Tenualosa ilisha (Hamilton, 1822) and T. toli (Valenciennes, 1847) (Teleostei, Clupeidae), in Malaysian waters

“…Morphological characters are ineffective to distinguish species at some stages of development (Ward et al 2009). Several authors have suggested that molecular genetic analyses are necessary for precise species confirmation (Arai et al 2015, Arai and Wong 2016, Abdul Kadir et al 2017.…”

“…The identification of tropical shads to species solely on morphological characters is difficult because of similarities and overlapping characteristics which can lead to misidentifications (FAO 2012, Arai and Amalina 2014). Recently, several authors have suggested that to be accurate, species identifications need to be validated by molecular genetic analyses (Arai et al 2015, Arai and Wong 2016, Abdul Kadir et al 2017. Thus, identification of tropical shad species require the use of both traditional morphological characters and molecular genetic analyses, which we do here for T. ilisha and T. toli from Malaysian waters.…”

New Records of the Goatfish, Upeneus Vittatus (Forsskal 1775) and Upeneus Supravittatus (Uiblein and Heemstra 2010) (Preciformes, Mullidae), From Saint Martin’s Island in the Bay of Bengal, Bangladesh

“…Morphological characters are ineffective to distinguish species at some stages of development (Ward et al 2009). Several authors have suggested that molecular genetic analyses are necessary for precise species confirmation (Arai et al 2015, Arai and Wong 2016, Kadir et al 2017. However, on the basis of morphological characters and DNA barcoding, U. vittatus and U. supravittatus were newly recorded in Bangladesh.…”