**1. Introduction**

Aquaculture has become a dynamic industry in constant development with the fastest growth food production sector of animal origin, even at a higher rate than human population, which could provide half of the fish consumption worldwide. However, its great development has turned out into great problems and challenges, based mainly on hyper-intensive production systems where the common denominator is high cultivation densities that generally cause physiological stress. Acute or chronic stress acts in a synergistic way to other environmental factors, negatively impacting productive parameters or increasing sensitivity to diseases produced by opportunistic pathogens as bacteria and viruses. Altogether finally translates into great economic losses to producers. Among the solutions for these problems is the use of expensive immunostimulant substances, so producers have opted to use and misuse antibiotics and/ or prophylactics to treat stress and its consequences. Antibiotics promote the resistance of target organisms and leave residues in the environment and in tissues, which has become a public health problem in some countries [1, 2]. For this reason, alternatives have been sought such as the use of probiotics [3], phytobiotics [4], and recently homoeopathy that has been investigating as a novel alternative to improve various productive aspects in the culture of aquatic organisms [5]. Homoeopathy is a branch of universal medicine based on the Law of Similars also expressed as "principle of like" (*Similia Similibus Curentur* = Like cures Like), and it is applied in ultra-diluted and succussed minimal doses. It is assumed that a substance that is applied in high doses (massively) generates a pathological symptomatology, so if it is applied in minimum doses (obtained by serial dilution and agitation), it can in turn cure it [6]. Homoeopathy derives from a Hippocratic medical concept proposed by the German physician Samuel Hahneman (1755–1843), who developed decimal (D; 1: 9), centesimal (C; 1: 99) millesimal (M; 1: 999) dilutions and other medicines, which are actually known as homoeopathic "dilutions" or "dynamisations." This process consists of serial dilution of mineral, plant and animal concentrate materials in water-ethanol vehicle, and vigorous agitation or "succussion" [7]. The starting point to obtain a certain dynamisation is a concentrate or Mother Tincture (MT), which is an alcoholic extract prepared from plants, animals, minerals, and even nanoparticulate metals [7]. In spite of its high dilution, it is possible to detect nanoparticles of the "ponderable active principle" (MT) in the dynamisations, even in high centesimal dilutions despite the fact that according to Avogadro's theory, they should not have a single molecule of MT [8]. Therefore, re-naming homoeopathy as "Adaptative Network Nanomedicine" has been recently proposed [9].

antibiotics, disinfectants) that when solving a problem generate undesirable side effects. In the last 10 years, scientific articles have been published on its application in freshwater fish native to Brazil, obtaining beneficial effects on growth, survival, hepatosomatic index, development of muscle fibres and lipid content in muscle. At Centro de Investigaciones Biológicas del Noroeste (CIBNOR, Mexico: www.cibnor.mx), we have studied the effects of homoeopathy to improve the culture of economically important marine species of molluscs, fish and shrimp. In this chapter, we show a selection of different research with preliminary or advanced results, related to the use of homoeopathy and its impact on zootechnic, biochemical, genomic and transcriptomic parameters in marine molluscs, fish and crustaceans. The results obtained suggest that homoeopathy is an eco-friendly alternative applicable in

aquaculture industry to improve various productive and health aspects.

and transcriptomic response

**1. Introduction**

68 Aquaculture - Plants and Invertebrates

**Keywords:** homeopathic medicine, marine molluscs, crustaceans and fish, growth, survival and biomass production, physiology and reproduction, genomic, metagenomic

Aquaculture has become a dynamic industry in constant development with the fastest growth food production sector of animal origin, even at a higher rate than human population, which could provide half of the fish consumption worldwide. However, its great development has turned out into great problems and challenges, based mainly on hyper-intensive production systems where the common denominator is high cultivation densities that generally cause physiological stress. Acute or chronic stress acts in a synergistic way to other environmental factors, negatively impacting productive parameters or increasing sensitivity to diseases produced by opportunistic pathogens as bacteria and viruses. Altogether finally translates into great economic losses to producers. Among the solutions for these problems is the use of expensive immunostimulant substances, so producers have opted to use and misuse antibiotics and/ or prophylactics to treat stress and its consequences. Antibiotics promote the resistance of target organisms and leave residues in the environment and in tissues, which has become a public health problem in some countries [1, 2]. For this reason, alternatives have been sought such as the use of probiotics [3], phytobiotics [4], and recently homoeopathy that has been investigating as a novel alternative to improve various productive aspects in the culture of aquatic organisms [5]. Homoeopathy is a branch of universal medicine based on the Law of Similars also expressed as "principle of like" (*Similia Similibus Curentur* = Like cures Like), and it is applied in ultra-diluted and succussed minimal doses. It is assumed that a substance that is applied in high doses (massively) generates a pathological symptomatology, so if it is applied in minimum doses (obtained by serial dilution and agitation), it can in turn cure it [6]. Homoeopathy derives from a Hippocratic medical concept proposed by the German physician Samuel Hahneman (1755–1843), who developed decimal (D; 1: 9), centesimal (C; 1: 99) millesimal (M; 1: 999) dilutions and other medicines, which are actually known as homoeopathic "dilutions" or "dynamisations." This process consists of serial dilution of mineral, plant and animal concentrate materials in water-ethanol vehicle, and vigorous agitation or "succussion" [7]. The starting point to obtain a certain dynamisation is a concentrate or Mother Tincture (MT), which is an alcoholic extract prepared from plants, animals, minerals, and even nanoparticulate metals [7]. In spite Homoeopathy has the peculiarity of stimulating the self-recovery of dynamic homeostasis when it has been lost due to exogenous and/or endogenous factors. Therefore, it does not focus on "the disease" but on the manifestations and intrinsic defence mechanisms of the "patient." It offers "signals" of systemic action to the treated individual to promote its selfregulation to recover homeostasis, and as it uses ultra-diluted minimal doses, it does not leave residues in the organism or in the environment. As a counterpart, the other medicine known as "allopathy" derives from a galenic concept based on the "principle of opposites" and the application of massive doses of various chemotherapeutic agents officially classified as antimicrobial, anti-viral, anti-inflammatory, anti-spasmodic, anti-histaminic, anti-fever and other "anti" drugs. Homoeopathic medicines can be administered to any living being, including terrestrial and aquatic plants, wild animals in captivity and breeding, as well as freshwater and marine species of commercial interest [7]. It has been widely used in human, animal and plant medicine because it induces specific responses and increases immunity, favouring resistance to pathogens under stressing situations, promoting a better post-infection recovery and improving internal dynamic homeostasis [5, 6, 10].

In Mexico, homoeopathy is recognised as a therapy of alternative medicine, and its practice was authorised by presidential decree in July 31, 1895; today its study and practice is officially recognised in the general health law (2015), and only health professionals can prescribe homoeopathic medicines, which must have an official code. This is the way homoeopathic medicines are differentiated from products like herbs for infusion and herbal remedies. In countries such as Brazil, there are homoeopathic medicines exclusively for veterinary use, for marine and freshwater fishes, registered with the Ministry of Agriculture. Important and promising results have been reported in freshwater organisms, mainly Nile Tilapia *Oreochromis niloticus* and Pacu *Piaractus mesopotamicus* [11–13]. Taking into account these antecedents, this chapter compiles not only the experimental results obtained in marine organisms, such as molluscs, fish and crustaceans when treated with commercial homoeopathic medicines for human use and approved by Federal Health Law and Health Ministry of México but also other ones that have been designed and developed at Centro de Investigaciones Biológicas del Noroeste (CIBNOR) in La Paz, Baja California Sur, Mexico.

For the purposes of this chapter, commercial drugs for human use have been utilised in the form of liquid hydro-alcoholic dynamisations (Similia® Laboratories, Mexico), injectable aqueous dynamisation (Rubiopharma®, Mexico) or sugar impregnated with homoeopathic complexes (Arenales Homoeopathy®, Brazil). They were considered "stock dynamisations," from which the respective "work dynamisations" were obtained through a serial process of dilution-succussion decimal or centesimal. Other non-commercial medicines were designed and developed at CIBNOR, from bacterial products (nosodes). This chapter deals with unitary or complex laboratory treatments used and registered with the Mexican Ministry of Health, such as Similia® and Rubiopharma® and a Cuban drug of Labiofam®, which will be described as follows: *Passiflora incarnata, Valeriana officinalis, Ignatia* amara and *Zincum valerianicum* of Similia® (PaV); Cyme-Heel, Gal-Heel, Hepa-Heel, Mucs-Heel and Chol-Heel of Rubiopharma*®* (INM); Endecto (END) and Infecçoes (INF) of Arenales Homoeopathy®; *Phosphoric acid* (PhA), *Phosphoric acid* (AcF), *Silicea terra* (SiT), *Sodium methasilicate* (MsS), Scorpion toxin Vidatox® (ViT); *Calcium sulphuricum* (CaS); *Hepar sulphuris* (HeS), *Ferrum phosphoricum* (FeP); *Zincum phosphoricum* (ZiP); *Magnesium phosphoricum* (MaP), *Mercurius solubilis* (MeS). Also, other nosode-type homoeopathic medicines from *Vibrio* compounds (ViP, ViA) were applied. These and other nosode type HOM-products have been designed by CIBNOR that is processing the respective trademark and industrial property titles (Office for industrial protection and technology transfer; OTT-CEPAT/CIBNOR; www.cibor.gob.mx). Ethanol (ET) and no-HOM nor ethanol (NT) were used as control treatments. Homoeopathic medicines (HOM) were sprinkled on balanced food or inert sugar pills or added directly to culture seawater.
