Enteromiuspallidus was described by Smith in 1841 without a designated type specimen for the species. Herein, we designate a specimen from the Baakens River system as a neotype for E.pallidus and provide a thorough description for this species to facilitate ongoing taxonomic revisions of southern African Enteromius. Enteromiuspallidus can be distinguished from the other minnows in the "goldie barb group" by having an incomplete lateral line, lack of distinct chevron or tubular markings around lateral line pores, absence of a distinct lateral stripe, absence of wavy parallel lines along scale rows and lack of black pigmentation around the borders of the scales. We provide mtDNA COI sequences for the neotype and an additional specimen from the Baakens River as DNA barcodes of types and topotypes are a fundamental requirement for further taxonomic studies.
The genus Ceratothoa Dana, 1852, is revised for Australian waters. Ceratothoa is represented in Australia by nine species, including two new species: Ceratothoa barracuda sp. nov. described from Cairns and Ceratothoa globulus sp. nov. described from Lord Howe Island. Ceratothoa imbricata Fabricius, 1775 is redescribed, with Ceratothoa trillesi (Avdeev, 1979) and Ceratothoa huttoni Filhol, 1885 placed into junior synonymy; the preferred hosts are species of the genus Trachurus (Carangidae). Ceratothoa banksii (Leach, 1818) is validated and brought out of synonymy with Ceratothoa imbricata; host species are from the families Kyphosidae, Scombridae, Latridae, Carangidae, Mugilidae, Salmonidae, Scatophagidae, Pomatomidae and Hemiramphidae. Species excluded from the Australian fauna are Ceratothoa trigonocephala (Leach, 1818) with an unknown host identity and type locality; and Ceratothoa lineata Miers, 1876a, that here is transferred to the genus Mothocya Costa, 1851, with Mothocya ihi Bruce, 1986 placed into junior synonymy. Ceratothoa contracta (Miers, 1880), the New Zealand Ceratothoa novaezelandiae Filhol, 1885 and the East Pacific Ceratothoa gaudichaudii (Milne Edwards, 1840) are regarded here as species inquirenda. A key to the Australian species of Ceratothoa is presented.
A checklist of parasitic cymothoids from Malaysian waters is presented based on available literature and material collected from 2010 to 2020. Most of the collected specimens were recorded from waters of Terengganu, east coast of Peninsular Malaysia (facing the South China Sea), whereas literature records were included from Sarawak, along the Miri coast of northwest Borneo. The checklist comprises 19 species in ten genera, seven of which are new records from Malaysia: Anilocra nemipteri Bruce, 1987; Ceratothoa barracuda Martin, Bruce & Nowak, 2015; Ceratothoa carinata (Bianconi, 1869); Cymothoa epimerica Avdeev, 1979; Elthusa sigani Bruce, 1990; Joryma engraulidis (Barnard, 1936) and Renocila richardsonae Williams & Bunkley-Williams, 1992. Eight new host records are based on collected specimens: Anilocra nemipteri was dorsally attached on Nemipterus nemurus (Bleeker, 1857), Nemipterus nematophorus (Bleeker, 1854), Nemipterus tambuloides (Bleeker, 1853) and Nemipterus thosaporni Russell, 1991 (family Nemipteridae); Ceratothoa carinata was found in the buccal cavity of Decapterus macrosoma Bleeker, 1851 (family Carangidae); Cymothoa eremita (Brunnich, 1783) was attached in the buccal cavity of Nemipterus tambuloides (Bleeker, 1853) and Nemipterus furcosus (Valenciennes, 1830); Elthusa sigani was found attached on the gills of Pterois russelli Bennett, 1831 (family Scorpaenidae), and Renocila richardsonae was attached on the caudal fin of Upeneus japonicus (Houttuyn, 1782) (family Mullidae). All cymothoid species listed here are known to have a Central Indo-Pacific distribution, with some ranging as far as the Western Indian Ocean. A cymothoid-host association is here listed from 28 fish families, with the most commonly reported from Carangidae (pompanos, jack mackerels, runners, scads), Engraulidae (anchovies), and Leiognathidae (ponyfishes, slipmouths). This paper is the first comprehensive review of both verified literature records and deposited specimens. A key for the family of Cymothoidae in Malaysian waters is given.
The chubbyhead barbs, a distinct group of fishes endemic to southern Africa, currently include eight valid species. Historically, Enteromius anoplus was the most widespread freshwater fish in South Africa due to synonymizations in the 1960s. It occurred in nearly every river system except coastal systems in the Cape Fold Ecoregion and the lower Orange River. However, a recent revision utilizing molecular and morphological analyses has led to significant taxonomic updates. Enteromius anoplus is restricted to the Gouritz River system, whereas Enteromius cernuus and Enteromius oraniensis have been revalidated and respectively confined to the Olifants and Orange River systems. Additionally, a new species Enteromius mandelai was described, with its range currently considered to encompass several river systems in the Eastern Cape. Despite these advances, the taxonomic status of fish previously assigned to E. anoplus from KwaZulu-Natal remained uncertain. In this study, an integrative approach, combining genetic analysis, morphological characteristics, and geographic data, was employed to resurrect Enteromius karkensis as a distinct species from E. anoplus. Enteromius karkensis is deeply genetically differentiated (3.99%-8.07% p-distance) from its congeners within the chubbyhead group. Morphologically, E. karkensis is easily distinguishable from its counterparts due to possession of a terminal mouth (vs. inferior in E. amatolicus), one pair of maxillary barbels (vs. two conspicuous pairs in E. motebensis, E. treurensis, and E. gurneyi), and a complete lateral line (vs. incomplete in E. anoplus and E. oraniensis). Furthermore, E. karkensis is differentiated from E. mandelai and E. cernuus by its long maxillary barbels that extend beyond the midpoint of the orbit. These findings highlight a consistent pattern from previous studies that show many freshwater fishes in South Africa have narrow geographic ranges. This emphasizes the importance of targeted conservation and management efforts, and our understanding of the biogeographic and evolutionary history of freshwater fishes in southern Africa.
Crustaceans possess a range of sensory organs crucial in sensory perception, communication, and various ecological functions. Understanding morphological and functional differences in antennae among species could validate taxonomic differentiation and ecological adaptations. The antennae morphology and ultrastructure of mud crab species within the Scylla genus are poorly understood, and their role in ecological adaptation and species differentiation remains unexplored. This study aimed to describe and compare the morphology and ultrastructure of antennae in Scylla olivacea, Scylla tranquebarica, and Scylla paramamosain. Antennae were carefully excised from each crab and subjected to morphological, morphometric, and ultrastructural analysis. The study revealed that the antennae of Scylla species exhibit similar overall morphology, with a series of segments that tapered toward the upper end. All species possess non-branched single setae on the upper end of each segment. The number of antennae segments varied between species, with S. paramamosain having significantly more segments than S. olivacea. Additionally, the length and width of antenna segments differed among the species, with S. tranquebarica having a rougher antenna surface compared to S. olivacea and S. paramamosain. Our findings suggest that Scylla's antennae are distinct between species, especially in the number of segments and setae size. Such difference might be related to ecological adaptation. The role of antennae in sensory perception and social behavioral cues in mud crabs warrants further investigation. This study serves as a foundational reference for future research on the taxonomy, ecological adaptation, and sensory behaviors in the Scylla genus. RESEARCH HIGHLIGHTS: Variations and similarities in morphology and ultrastructure of three Scylla species can be found in the antennae. Scylla paramamosain had significantly higher number of segments than Scylla olivacea in morphology feature. The antennae surface of Scylla tranquebarica was rougher than that of S. olivacea and S. paramamosain. Antennae of three Scylla species possess non-branched single setae.
The data available in this repository were gathered from Balok, the only most productive spawning site for horseshoe crabs Tachypleus gigas and Carcinoscorpius rotundicauda in East Coast of Peninsular Malaysia. The mangrove horseshoe crab, C. rotundicauda population and spawning data are available in the first table. The horseshoe crabs were retrieved from Balok River using 11.43 cm mesh size gill nets installed at the river mouth, the confluence and last meander. The arthropods were inspected for damage, abnormality and growth before their release into Balok River, particularly at the site of capture. Sediment samples were retrieved at their spawning grounds to ascertain sediment composition and size classifications which were also processed using Logarithmic Method of Moments. Water parameters like temperature, pH and salinity were also investigated during year 2016. All these information are compiled into the second table and arranged according to the period of data availability. The horseshoe crab catch data of years 2012, 2013, 2014, 2015 and 2016 were made available by artisanal fisher and compiled in the third and fourth table for inter-species comparison.
Carcinoscorpius rotundicauda and Tachypleus gigas may co-exist and share common spawning grounds elsewhere but at Balok (East Coast of Peninsular Malaysia), C. rotundicauda is an understudied species. Neglected as research candidate because of inaccessible spawning grounds, smaller size and less commercial value than T. gigas and also, difficulty to attain from the wild has made C. rotundicauda population status remaining unidentified at Balok. This standpoint drove the present attempt because anthropic activities like structure placement and mining are point-source for runoffs that load sediments into Balok River. While erosion-accretion events have altered Balok River width, the shore sediments in Balok Beach were transitioned between medium-fine and fine sand between years 2012 and 2016. Eventually by year 2016, the C. rotundicauda were depositing 5117 eggs in 91 nests from 200 to 1000 m range along this corridor facing South China Sea. From this yield, C. rotundicauda released 2880 eggs in 56 nests during the Southwest monsoon, 1254 eggs in 19 nests during the Northeast monsoon and 983 eggs in 16 nests during the Inter-monsoon seasons. Though female C. rotundicauda opted to lay their eggs in shallow burrows at lower shorelines, the absence of erosion and substantial silt and clay (>20%) deposition facilitates C. rotundicauda embryogenesis with brief periods of temperature and salinity shocks during day-time falling tides. This encourages C. rotundicauda to emerge with increasing abundance and carry out bi-monthly spawning at Balok Beach. In short, shore restoration initiatives like systematic boat docking, proper disposal of nets and waste and, periodic fish-catching operations were effectively led by the Balok fisher citizen scientist. This successful community joint-cooperation proves that citizen-led caretaking of degraded beaches offers marine life protection and are practical for coastal area management especially at areas where other oviparous animals such as turtles and crocodiles are harboured.
Peacock bass (Cichla spp.) originates from the Neotropical environments of Brazil and Venezuela but, through trade and smuggling for aquarium keeping, sport fishing and aquaculture, it is now an emerging concern. Yet, less is known for Cichla spp. distribution and its ability to invade new environments. Aimed to communicate on Cichla spp. ecology, biology and introduction schemes from Scopus, Web of Science, Google Scholar and also National Centre for Biotechnology Information, this review also contains management strategies for invading fish species. While Cichla spp. can displace native fish populations, this concern is explained using ecological functions, physiological demands, direct and secondary invasion, disease tolerance and parasite spillover. Briefly, Cichla spp. has rapid embryogenesis (72 h) and matures in short periods (11-12 months), giving it an advantage to colonize new environments. With a large appetite, this true piscivore gains territorial control over water bodies by making it their feeding and nursery grounds. Perceived as an emerging concern after becoming introduced, seal-off or sport fishing were used to manage Cichla spp. but, this practice is not sustainable for the entire ecosystem. Hence, we recommend bottom-up management that involves community participation because they interact with the fish and have knowledge about their environment.