Broodstock development, breeding, embryonic development and larviculture of spine-cheek anemonefish, Premnas biaculeatus (Bloch, 1790)

The broodstock development, breeding, embryonic development and larviculture of Premnas biaculeatus and different feeding and envrionmental conditioins are reported for the first tiem. The influence of enriched rotifer (Brachionus rotundiformis, Brachionus plicatilis) and non-enriched newly hatched Artemia nauplii along with microalgae (Chlorella marina, Nannochloropsis oculata and Isochrysis galbana) on larval rearing and survival was elucidated. Fishes in the length range of of 55 to 70 mm (presumptive male) and 120 to 150 mm (presumptive female) were selected for pair formation experiments along with single host sea anemone Heteractis magnifica. All the 10 pairs started spawning within four months after they were shifted to the breeding tanks. Eggs were laid in round patches or clutches at intervals of 15 to 20 days with an average of 2.09 ± 0.3 spawnings per month per pair giving an annual number of 1752 -11832 eggs per pair. Upon incubation for six days in complete darkness, 95-98% of the eggs hatched with the peak hatching between 1830 and 1930 hrs. On 20th day post-hatch (d.p.h.), most of the larvae metamorphosed to juveniles and began to shift from partially pelagic to epibenthic and the juveniles reached marketable size from 60th d.p.h. onwards

Life history pathways in false clown Amphiprion ocellaris Cuvier, 1830: A journey from egg to adult under captive condition

There is a vast literature on distribution, rearing conditions and behavioural studies of clownfishes. However, descriptive information on reproductive behaviour, early developments and life history pathways of Amphiprion ocellaris are scarce. In this study, 7 pairs of A. ocellaris having size 89 to 100 mm (presumptive females) and 40 to 60 mm (presumptive males) were developed through pair formation to generate information on breeding and spawning behaviour, egg morphology, and embryonic, larval, juvenile and adult developments. The spawning was found to be year-round with reproductive cycle of 12 to 15 days intervals and laid 300 to 1000 capsule shaped and adhesive type eggs. The eggs were 1.5-3.0 mm in length and 0.8-1.84 mm in width containing multiple oil globules of varying size and were pale yellow or white for initial two days, turned to black on 3rd to 5th day and silvery on 6th to 7th day of incubation

A robust sequential hypothesis testing method for brake squeal localisation

This contribution deals with the in situ detection and localisation of brake squeal in an automobile. As brake squeal is emitted from regions known a priori, i.e., near the wheels, the localisation is treated as a hypothesis testing problem. Distributed microphone arrays, situated under the automobile, are used to capture the directional properties of the sound field generated by a squealing brake. The spatial characteristics of the sampled sound field is then used to formulate the hypothesis tests. However, in contrast to standard hypothesis testing approaches of this kind, the propagation environment is complex and time-varying. Coupled with inaccuracies in the knowledge of the sensor and source positions as well as sensor gain mismatches, modelling the sound field is difficult and standard approaches fail in this case. A previously proposed approach implicitly tried to account for such incomplete system knowledge and was based on ad hoc likelihood formulations. The current paper builds upon this approach and proposes a second approach, based on more solid theoretical foundations, that can systematically account for the model uncertainties. Results from tests in a real setting show that the proposed approach is more consistent than the prior state-of-the-art. In both approaches, the tasks of detection and localisation are decoupled for complexity reasons. The localisation (hypothesis testing) is subject to a prior detection of brake squeal and identification of the squeal frequencies. The approaches used for the detection and identification of squeal frequencies are also presented. The paper, further, briefly addresses some practical issues related to array design and placement. (C) 2019 Author(s)

Isolation, identification and culture of the marine rotifer Colurella adriatica Ehrenberg, 1831 (Family: Lepadellidae) from Andaman & Nicobar Islands: A promising live feed for larval rearing of high value shellfishes and finfishes

An extremely small rotifer was isolated from the micro zooplankton samples collected during February, 2014 from Havelock islands of Andaman and Nicobar Islands. The species was identified as Colurella adriatica Ehrenberg, 1831 (Family: Lapadellidae). Its lorica length under culture period ranged from 47.530 to 98.868 μm and width from 34.308 to 56.277 μm. The size of the eggs, neonates and adults are also documented. Comparison of size of C. adriatica with Brachionus plicatilis (L type) and B. rotundiformis (S and SS type) revealed that C. adriatica is smaller in length and width than the SS-type rotifer which is currently used as a first feed in marine tropical fish larval rearing. However, the larvae of many marine food fishes including groupers and high value marine ornamental fishes are unable to consume the SS-type rotifers as a first feed due to their extremely small mouth gape. The culture of C. adriatica was carried out using Nannochloropsis oculata Diet-I), N. oculata and yeast (0.01g/litre) (Diet-II), Yeast (0.01g/litre) alone (Diet-III). Average population density of C. adriatica with these diets reached a maximum of 1000 nos. of individuals /ml on 10th day of culture on feeding with Diet-I; 950 nos. /ml on 14th day (Diet-II) and 650 nos. /ml on 15th day of culture (Diet-III). Diet I &II and Diet II &III did not show any significant difference (P>0.05) whereas, Diet I and III showed significant difference (P<0.01). Preliminary studies of C. adriatica as a feed to the larvae of Stenopus hispidus, Lysmata amboinensis and Pomacentrus caeruleus showed better survival than larvae fed with B. routundiformis during first phase of larval rearing

Marine ornamental fishes and their breeding: CMFRI initiatives

The marine ornamental fish trade is a sunrise industry in aquaculture and has become a growing industry worldwide. As a result the trade of marine ornamentals has been expanding in recent years and has grown into a multimillion dollar enterprise mainly due to the emergence of modern aquarium gadgets and technologies for setting and maintenance of miniature reef aquaria. Since the marine ornamental trade is operated throughout the tropics, the global marine ornamental trade is estimated at US$ 200- 330 million. Since India is endowed with a vast resource potential of marine ornamentals distributed in the coral seas and rocky coasts with patchy coral formations and the increasing the demand in the domestic trade, it appears very much lucrative for India to venture into this industry

Ethnomedicine Against Jaundice Used by Gond Tribes of Adilabad District, Andhra Pradesh, India

The present investigation was performed in order to enumerate the medicinal plants that gond tribes uses for the treatment of jaundice in Adilabad district, Andhra Pradesh, India. The study revealed that totally 12 plants belonging to 9 families were used to cure jaundice . The plants were used either separately or in combination with some other plant parts.

String spectra near some null cosmological singularities

We construct cosmological spacetimes with null Kasner-like singularities as purely gravitational solutions with no other background fields turned on. These can be recast as anisotropic plane-wave spacetimes by coordinate transformations. We analyse string quantization to find the spectrum of string modes in these backgrounds. The classical string modes can be solved for exactly in these time-dependent backgrounds, which enables a detailed study of the near singularity string spectrum, (time-dependent) oscillator masses and wavefunctions. We find that for low lying string modes(finite oscillation number), the classical near-singularity string mode functions are non-divergent for various families of singularities. Furthermore, for any infinitesimal regularization of the vicinity of the singularity, we find a tower of string modes of ultra-high oscillation number which propagate essentially freely in the background. The resulting picture suggests that string interactions are non-negligible near the singularity.Comment: Latex, 30pgs; v2. minor clarifications, references adde

Armour Protection and Affordable Protection for Futuristic Combat Vehicles

Protection creates a shift in the internal paradigm of the soldier and leads to multiplied psychological stamina for moving fearlessly in the battlefield which generates a major force-multiplier effect. Hence, the mechanized forces are still likely to be one of the dominant forces on the futuristic battlefield and would be the primary target of enemy forces capable of engaging from tank guns up to 4-5 km in a direct fire mode and up to 8-10 km in an indirect fire modes. Increased protection is possible only using advanced armour technology. Throughout the history of warfare, materials technologies have had a significant impact on land-combat force capabilities. Armour materials have progressed through improvements in metallic systems and development of advanced, lightweight (low areal density) composite materials. The advancements in ceramic systems have further improved the performance. Similarly, the advances in development of explosive reactive armour has generated efficient armour system against all contemporary high explosive antitank (HEAT) ammunition and missile threats for armoured vehicles. Yet, to achieve armour performance exceeding that of the current light combat vehicles and main battle tanks for new vehicular systems, weighing significantly less than the present combat vehicles, advances in new armour materials, systems, and survivability technologies are required. This paper describes various approaches and advancements in the metallic, ceramic, and composite armour materials and new dynamic armour systems that are essential to improve the survivability of armoured vehicles in the futurisitic multi-spectral battlefied scenarios.Defence Science Journal, 2011, 61(4), pp.394-402, DOI:http://dx.doi.org/10.14429/dsj.61.36