Length–weight and length–length relationships of some small indigenous fish species from the Mathabhanga River, southwestern Bangladesh

The present study describes the length–weight (LWR) and length–length (LLR) relationships for eight important small indigenous fish species (SIS) from the Mathabhanga River, southwestern Bangladesh, namely Amblypharyngodon mola (Hamilton, 1822), Channa punctata (Bloch, 1793), Hyporamphus quoi (Valenciennes, 1847), Macrognathus aculeatus (Bloch, 1786), M. pancalus (Hamilton, 1822), Nandus nandus (Hamilton, 1822), Puntius sophore (Hamilton, 1822), and Setipinna phasa (Hamilton, 1822). A total of 2543 specimens used for this study was caught by traditional fishing gear from January to December 2005. To the best knowledge of the authors, this study presented the first reference on LWR and LLR for these species from Bangladeshi waters.     

Length–weight relationship of six indigenous fish species from Deepor beel,a Ramsar site in Assam,India

Length–weight relationships for six small indigenous fish species, namely: Trichogaster chuna (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Trichogaster fasciata Bloch & Schneider, 1801, Chanda nama Hamilton, 1822, Parambassis lala (Hamilton, 1822), and Macrognathus aral (Bloch & Schneider, 1801) were studied for the first time from Deepor beel, a Ramsar site (589 ha water spread area) located in Assam, India. A total of 617 fish specimens were collected for the present study on a monthly basis from February to August in 2016 from landing centres adjoining the beel. In the present study, b value ranges from 2.778 to 3.215, which is within the normal range. The LWRs for these six fish species from Deepor beel had not yet been reported for FishBase.     

The development of neuromasts in Cirrhina mrigala Ham. Buch. (Cyprinidae) and Ophicephalus (Channa) punctatus Bloch (Channidae)

The development of neuromasts was studied in two species of teleosts, Cirrhina mrigala Ham. Buch. and Ophicephalus punctatus Bloch, and the findings are presented and discussed. It has been discovered, in the course of this investigation, that a neuromast arises by a process of invagination — a fact hitherto not reported. The occurrence of the dorsal lateral line and the accessory lateral line of the trunk, in addition to the main lateral line, has also been reported for the first time for teleosts, although known for other bony fishes.     

Saprolegnia australis R. F. Elliott 1968 infection in Prussian carp Carassius gibelio (Bloch, 1782) eggs and its control with herb extracts

In order to control saprolegniosis in Prussian carp (Carassius gibelio (Bloch, 1782) eggs, it is important to screen herb extracts as potential anti‐Saprolegnia drugs in Prussian carp hatcheries. For this purpose, an oomycete water mould (strain SC) isolated from Prussian carp [Carassius gibelio (Bloch, 1782)] eggs suffering from saprolegniosis was characterised morphologically as well as from ITS rDNA sequence data. Initially identified as a Saprolegnia sp. based on its morphological features, the constructed phylogenetic tree using the neighbour joining method further indicated that the SC strain was closely related to Saprolegnia australis R. F. Elliott 1968 strain VI05733 (GenBank accession no. HE798564 ), and which could form biofilm communities as virulence factors. In addition, aqueous extracts from forty Chinese herbs were screened as possible anti‐Saprolegnia agents. Among them, a 1 g ml^?1 extract from Radix sanguisorbae was the most efficacious anti‐Saprolegnia agent, indicated by the minimum inhibitory concentration that was as low as 256 mg L^?1. Relative survival of 73 and 88% was obtained against the SC strain in fish eggs at concentrations of 256 and 1280 mg L^?1, respectively. This is the first known report of Saprolegnia australis R. F. Elliott 1968 infection in C. gibelio (Bloch, 1782) eggs involving the screening of R. sanguisorbae extracts as potential anti‐Saprolegnia agents.     

Carcass characteristics of marketable size striped murrel,Channa striatus (Bloch, 1793)

The carcass and commercial yield traits of Channa striatus were evaluated. Experimental fish were 8‐month‐old snakehead murrels (Channa striatus) weighing 500–700 gm, reared in earthen ponds and cultivated intensively at a rate of 10 000 fingerlings/ha. The fish were given formulated feed for a period of 1 year. Morphometric parameters were measured along with carcass, filleting, and offal traits. The murrel head yield (28.7%) as well as scales and skin yield (11.92%) were recorded. Dressed murrel (evisceration yield) was 89.59% of the live weight. Dressed percentage (minus the head, skin and viscera) was 50.72%. Average meat‐to‐bone filleting ratio was 3.43 of marketable size murrels. Insignificant accumulations of fat deposits on the lining of the abdominal cavity and coating the bowels were noted.     

Length–weight and length–length relationship of Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika lagoon,India

Current study provides basic information on Length–weight relationship (LWR) and length‐length relationship (LLR) of three fish species of genus Thryssa (Clupeiformes: Engraulidae) i.e., Thryssa purava (Hamilton, 1822), Thryssa polybranchialis Wongratana, 1983 and Thryssa mystax (Bloch & Schneider, 1801) from Chilika Lagoon, India. Samples were collected during the monsoon (July) and post‐monsoon (November) seasons in 2016 and during the pre‐monsoon season (May) in 2017, using screen barrier nets (mesh size 8–18 mm) and gill nets (mesh size 14 and 16 mm). The b values were determined from LWRs as 3.026 for Thryssa purava, 3.326 for Thryssa polybranchialis and 3.081 for Thryssa mystax.     

Babesiosoma ophicephali n. sp. from the Freshwater Teleost Ophicephalus punctatus Bloch

SYNOPSIS. Babesiosoma ophicephali n. sp. (Babesiidae; Haemosporidia), from the red blood cells of the freshwater teleost fish Ophicephalus punctatus Bloch, collected from suburbs of Calcutta, is described. Giemsa-stained films of blood from the caudal region of 20 fishes were examined, and 2 fishes were found to be infected. The genus Babesiosoma is described for the first time in India. The systematic position of the parasite is discussed in detail.     

Ethology and ecology of cichlid fishes of the genus Etroplus in Sri Lanka: preliminary findings

Synopsis The Asian cichlid fishes, Etroplus maculatus (Bloch) and E. suratensis (Bloch) were observed in their natural habitat. Ecological and behavioral interactions of these species have not been previously reported. E. suratensis benefits from being cleaned by E. maculatus; it is doubtful the ingestion of parasites and fungi is of much direct benefit to E. maculatus. The advantage to E. maculatus is more likely the survival and reproductive success of adult E. suratensis which in turn provide eggs and eleutheroembryos for the egg-young predatory habit of E. maculatus. Predation is lessened by age-specific crypticity of E. suratensis. E. maculatus displays a unique behavior during its parental cycle where both parents actively defend their young until they are nearly sexually mature and almost the size of the parents. Adult E. suratensis engage in altruistic multiple parental care where several adults care for a single brood that presumably were spawned by only two of the adults. Such behavior has not been reported previously for fish.     

Reproductive guilds (maturation,spawning frequency and fecundity) in the black pomfret,Parastromateus niger (Carangidae) in the Kuwaiti waters of the Arabian Gulf

Oogenesis, oocyte maturation pattern, spawning rhythm, spawning frequency, batch fecundity and oocyte diameter–frequency distribution of the black pomfret, Parastromateus niger (Bloch, 1795) in Kuwaiti waters were investigated from October 2003 to September 2005, using histological and morphological methods. The process of development is divided into four major phases: (i) primary growth phase; (ii) secondary growth phase; (iii) maturation phase; and (iv) spawning phase, followed by the regressed phase. Development of the yolky oocyte is an asynchronous process resulting, by the time of oocyte maturation, in a clear differentiation between a ready batch of oocytes (ready for spawning) and a reserve pool. Consequently, P. niger is capable of spawning multiple times throughout the reproductive season. Spawning frequency estimates, based on final oocyte maturation (FOM) method indicated that the species spawns once every 2.8 days during an 8‐month spawning season lasting from February to September, with a potential annual number of 22.4 spawns. Batch fecundity (BF) (2132–2001 648, mean 406 010 eggs), was significantly positively related to both standard length (SL) (P < 0.05) and ovary‐free body weight (OFBW) (P < 0.05), both parameters being good predictors of BF (r² = 30.8% for SL, from 22 cm onwards, and r² = 29.6% for OFBW, from 129.5 g onwards). No significant differences in monthly BF were found throughout the spawning season. Relative batch fecundity was 336 eggs/g OFBW; thus, estimate for potential annual relative batch fecundity was 7526 eggs g^?1 OFBW. The oocyte diameter–frequency distribution analysis revealed a multimodal distribution (at 100–200, 300–400 and 500–700 μm), confirming the evidence of multiple spawning.     

Length–weight relationships of three freshwater fish species from Rupnaryan and Kangsabati River,West Bengal,India

The length–weight relationships (LWRs) of three freshwater fish species from the Kangsabati and Rupnaryan river in West Bengal, India are presented, namely as Amblypharyngodon microlepis (Bleeker, 1853), Parambassis lala (Hamilton, 1822) and Macrognathus aculeatus (Bloch, 1786). Gill‐nets (mesh sizes with 0.5 cm–4 cm), cast‐nets (up to 1 × 1 cm mesh size with up to 4.0 m² area) and scoop‐nets (0.3 × 0.3 cm and 0.5 × 0.5 cm mesh size) were used from January, 2017 to April, 2018. Sampling was done every 15 days during this period. The value of parameter “b” ranged from 2.751 to 2.895 with highly significant correlations (r² > 0.95).     

Length-weight relationships of eight reservoir fish species in Puerto Rico

Length-weight relationships (LWR) of eight fish species, Lepomis auritus (Linnaeus, 1758), Amphilophus labiatus (Günther, 1864), Oreochromis mossambicus (Peters, 1852), Cichla ocellaris Bloch & Schneider, 1801, Parachromis managuensis (Günther, 1867), Vieja melanura (Günther, 1862), Pterygoplichthys pardalis (Castelnau, 1855), and Gobiomorus dormitor Lacepède, 1800, collected by electrofishing and gillnetting from ten reservoirs in Puerto Rico were determined using 3,557 individual fish records collected between 1998 and 2014. All LWRs were significant with r² values ranged from 0.900 for A. labiatus (Günther, 1864) to 0.996 for C. ocellaris Bloch & Schneider, 1801. The LWR parameter b ranged from 2.807 for P. pardalis (Castelnau, 1855) to 3.180 for C. ocellaris Bloch & Schneider, 1801. Data presented herein expand the knowledge base for these species as they have limited or no LWR data available. Also, our samples provide a new maximum length data for P. pardalis (Castelnau, 1855).     

Observations on the life-cycles of two haploporid trematodes,Carassotrema bengalense Rekharani & Madhavi, 1985 and Saccocoelioides martini Madhavi, 1979

The life-cycles of two species of haploporid trematodes, Carassotrema bengalense Rekharani & Madhavi, 1985 and Saccocoelioides martini Madhavi, 1979, are illustrated. The molluscan host of the two species is the prosobranch gastropod Stenothyra blanfordiana (Nevill), which occurs in abundance in Chilka Lake, a large brackish-water lagoon. The cercariae are gymnocephalous, bi-ocellate and distomate. The cercaria of C. bengalense is characterised by the presence of thin lateral expansions of the tail, long tubular caeca, dense cystogenous glands and a Y-shaped excretory bladder. The cercaria of S. martini, on the other hand, has a simple tail, a prominent pharynx, short elliptical caeca lined by tall cells and an I-shaped excretory bladder. Both of the cercariae encyst on algae. Adults of C. bengalense occur in Mugil cephalus L. and Valamugil cunnesius (Val.), while those of S. martini occur in M. cephalus, Liza macrolepis (Smith), Etroplus suratensis (Bloch) and Hilsa ilisha (Hamilton).     

Host specificity of <Emphasis Type="Italic">Anagrus epos</Emphasis>: a potential biological control agent of <Emphasis Type="Italic">Homalodisca vitripennis</Emphasis>

Anagrus epos Girault (Hymenoptera: Mymaridae) is a candidate for a classical biological control program targeting the glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), in California. Because mass production of GWSS is expensive and labor-intensive, a factitious host that is more economical to produce is desirable to mass produce A. epos for colonization and augmentation efforts. Here, we report the results of host specificity tests and potential rearing techniques for A. epos under laboratory conditions. Females discriminated and oviposited into eggs of seven cicadellid species: H. vitripennis, Circulifer tenellus (Baker), Erythroneura variabilis Beamer, Amblysellus grex (Oman), Graphocephala atropunctata (Signoret), Macrosteles severini Hamilton, and H. liturata Ball, and two cerambycid species: Phoracantha recurva Newman and P. semipunctata (F.). Anagrus epos successfully completed development in the eggs of H. vitripennis, C. tenellus, E. variabilis, A. grex, G. atropunctata, M. severini, and H. liturata. The use of a factitious host and potential nontarget effects of this generalist parasitoid are discussed.     

Length–weight and length–length relationships of four species of genus Pethia and genus Puntius from wetlands of Lakhimpur district,Assam, India

Length–weight relationships (LWR) and length–length relationships (LLR) were estimated for four species, namely, Puntius sophore (Hamilton, 1822), Puntius chola (Hamilton, 1822), Pethia ornatus (Vishwanath & Laisram, 2004) and Pethia ticto (Hamilton, 1822) collected from different wetlands of Lakhimpur, Assam. The values of the parameter slope (b) in the LWR were 3.30 for Puntius sophore, 3.22 for Puntius chola, 2.61 for Pethia ornatus and 3.27 for Pethia ticto. The relationships among TL, FL and SL were all linear (r² > 0.95).     

The rotifer fauna and population dynamics of Lake Studer 2 (Kerguelen Archipelago) with description ofFilinia terminalis kergueleniensis n. ssp. and a new record ofKeratella sancta Russel 1944

Two species of Anabas Cuvier, 1816 (Osteichthyes: Anabantidae): A. testudineus (Bloch, 1795) and A. oligolepis Bleeker, 1855 are widely distributed in India. Since both species are represented in one habitat — Lake Kolleru, and are very closely related, they were compared using starch gel electrophoresis. Electrophoretic separation of proteins of eye lens, skeletal muscle and heart muscle revealed differences such as i) absence of one protein fraction in one of them, ii) mobility and iii) staining intensity of some of the bands. The esterase (non-specific) patterns of serum, liver, kidney, skeletal muscle, heart muscle and eggs also showed differences. The LDH fraction of eye lens showed a difference in mobility.     

Length‐weight relationships (LWRs) of four freshwater fish species from the Brahmaputra and Barak river basins,northeast India

The present study describes the length‐weight relationships (LWRs) were determined for four fish species, collected from the Brahmaputra and Barak river basins in northeast India using cast nets (2.5 × 1 m; 10–15 mm mesh size) and gillnets (30 × 0.9 m; 5–10 mm mesh size), from June 2016 to July 2017. The b values in LWRs were determined as 2.70 for Badis tuivaiei Vishwanath & Shanta, 2004, 2.93 for Canthophrys gongota (Hamilton, 1822), 2.62 for Glyptothorax botius (Hamilton, 1822), and 3.22 for Gogangra viridescens (Hamilton, 1822).     

Length–weight relationships of four indigenous freshwater fish species from Khalsi wetland in lower Ganga basin,West Bengal,India

The length‐weight relationships of four indigenous freshwater fishes Parambassis lala (Hamilton, 1822), Trichogaster lalius (Hamilton, 1822), Puntius terio (Hamilton, 1822), and Pethia phutunio (Hamilton, 1822) were determined. Fish samples were collected during December 2013 to May 2015 from Khalsi, a floodplain wetland along the tributary of the River Ganges in West Bengal state, India using different types of gear (castnets, gillnets and drag nets, stretched mesh sizes of 15–20 mm, 20–30 mm and 5–10 mm, respectively). This is the first report on the length–weight relationship parameters of these four species.     

Length–weight relationships of four freshwater cyprinid species from a tributary of Ganga River Basin in North India

This paper provides length‐weight relationships (LWRs) for four freshwater cyprinid fish species, namely Barilius bendelisis (Hamilton, 1807), Bangana dero (Hamilton, 1807), Chagunius chagunio (Hamilton, 1807) and Labeo dyocheilus (McClelland, 1839) from the Kosi River, a tributary of the River Ganga in northern India. Altogether 848 specimens were caught bimonthly (for B. bendelisis) and quarterly for the other three species between March 2013 and December 2014 using cast nets (9 m length, 9 m width and 1/2 cm mesh size). LWRs for two of the four species (B. dero and C. chagunio) are recorded for the first time. The present study results will be useful for fishery researchers, management and conservation in this least‐explored tributary of the Ganga River Basin.     

Length–weight relationships of Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822) and Barilius barna (Hamilton, 1822) from Manas River in Assam,India

The present study describes the length–weight relationships (LWRs) for three ornamental hill stream fish species from the Manas River in Assam, India, namely, Barilius bendelisis (Hamilton, 1807), Barilius shacra (Hamilton, 1822), and Barilius barna (Hamilton, 1822). Fishes were collected on a monthly basis from March 2015 to February 2016 with cast nets (270 cm, 1.2 cm) and gillnets (7,500 × 130 cm, 5 cm). This is the first information on LWR data for two of the species.     

Key to the eggs of the equid stomach bot flies Gasterophilus Leach 1817 (Diptera: Gasterophilidae) utilizing scanning electron microscopy

Abstract. A key to the eggs of the equid stomach bot flies is presented. Scanning electron photomicrographs of eggs are used to illustrate differences among the eight Gasterophilus species. The eggs include those of G.haemorrhoidalis (Linnaeus, 1758), G.inermis (Brauer, 1858), G.intestinalis (De Geer, 1776), G.meridionalis (Piller and Evans, 1926), G.nasalis (Linnaeus, 1758), G.nigricornis (Loew, 1863), G.pecorum (Fabricius, 1794), and G.ternicinctus Gedoelst, 1912. The eggs of G.meridionalis and G.ternicinctus are shown for the first time. Egg profile is the same for a particular species and is used as a key character for egg identification. Colour of eggs is used in some couplets but only as a supplemental character. Absence or presence of striae on the eggs is used as a primary contrasting character to separate G.pecorum from the other seven species. Shape of the striae varies on eggs of the same species, even those dissected from the same specimen, and is therefore deemed an unreliable taxonomic character for further separation of the Gasterophilus species. Eggs of the same species taken from specimens throughout the world appear the same in profile. Two sets of eggs require close inspection for adequate identification: G.inermis and G.nigricornis separated primarily by the shape of the microphylar region; and G.intestinalis and G.ternicinctus separated by the shape of the egg ventrum. All other eggs have very unique and distinctive profiles. Only G.pecorum was found to possess the Type-II egg attachment organ (AO) used for adherence of the egg to plants or flat surfaces. The eggs of the remaining seven species possess a Type-I AO used to attach the eggs to hair shafts. The type of AO and the degree that the Type-I AO is extended posteriorly were used as key characters in the first and second couplet respectively.