Tag: growth

Estimating somatic growth of fishes from maximum age or maturity

Two new data-limited methods to estimate somatic growth, applicable to species with indeterminate growth such as fishes or invertebrates.

Somatic growth rate is a central life-history parameter, especially in species like fishes or invertebrates which grow throughout their lives. It is needed in conservation and fisheries management but it can sometimes be tricky to estimate.

In a recent study published in the journal Acta Ichthyologica et Piscatoria, Dr. Rainer Froese of the Helmholtz Centre for Ocean Research proposes new simplified methods for somatic growth estimation.

A school of Jacks pass overhead at Viuda (Widow) dive site, in Coiba National Park, Panama, a UNESCO World Heritage site. Photo by LASZLO ILYES under a CC-BY 2.0 license.

Dr. Froese presents two new data-limited methods to estimate somatic growth from maximum length combined with either length or age at maturation or with maximum age. They are applicable to a wide range of species, sizes, and habitats. Using these new methods, growth parameter estimates were produced for the first time for 110 fish species.

“The growth estimates derived with the new methods presented in this study appear suitable for consideration and preliminary guidance in applications for conservation or management,” Dr. Froese points out in his study.

He goes on to suggest that journals accept growth estimates performed with the new methods as new knowledge, if they are the first for a given species.

In order to facilitate the conservation and management of natural resources, FishBase will continue to compile growth parameters, including results obtained with these new methods.

Research article:

Froese R (2022) Estimating somatic growth of fishes from maximum age or maturity. Acta Ichthyologica et Piscatoria 52(2): 125-133. https://doi.org/10.3897/aiep.52.80093

Medicinal mushroom newly reported from Thailand helps reveal optimum growth conditions

Globally recognised medicinal mushroom is reported for the first time in Thailand. The study also presents the first assessment of the optimum growth conditions for the species.

A species of globally recognised medicinal mushroom was recorded for the first time in Thailand. Commonly referred to as lingzhi, the fungus (Ganoderma tropicum) was collected from the base of a living tree in Chiang Rai Province, Northern Thailand. Additionally, the study reports the first assessment of the optimum conditions needed for the species to grow its mycelia (the vegetative part of a fungus consisting of a branching network of fine, thread-like structures) and spread its colony.

The discoveries are published in the open-access journal MycoKeys by a research team from the Chinese Academy of Sciences, University of Chinese Academy of Sciences, World Agroforestry Centre, Kunming Institute of Botany (China) and Center of Excellence in Fungal Research, Mae Fah Luang University (Thailand), led by Thatsanee Luangharn.

Over the last centuries, the studied mushroom and its related species in the genus Ganoderma have been used extensively in traditional Asian medicines due to their natural bioactive compounds, including polysaccharides, triterpenoids, sterols, and secondary metabolites, which are used in the treatment of various diseases. Other compounds derived from lingzhi, such as the studied species, also demonstrate antimicrobial activities. The medicinal use of these mushrooms is recognised by the World Health Organization and they are featured in the Chinese Pharmacopoeia.

The studied mushroom belongs to a group known to be parasitic or pathogenic on a wide range of tree species. The species is characterised with strongly laccate fruiting bodies and a cap with distinctly dark brown base colour and reddish shades. It grows to up to 7-12 cm in length, 4-8 cm in width and is up to 1.5 cm thick. While the mushroom has so far been widely reported from tropical areas, including mainland China, Taiwan and South America, it had never been recorded from Thailand.

During their research, the scientists found that mycelial production for Ganoderma tropicum is most successful on Potato Dextrose Agar, Malt Extract Agar, and Yeast extract Peptose Dextrose Agar, at a temperature of 25-28 °C and 7-8 pH. Unfortunately, mushroom fruiting was not achieved in the experiment.

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Original source:

Luangharn T, Karunarathna SC, Mortimer PE, Hyde KD, Thongklang N, Xu J (2019) A new record of Ganoderma tropicum (Basidiomycota, Polyporales) for Thailand and first assessment of optimum conditions for mycelia production. MycoKeys 51: 65-83. https://doi.org/10.3897/mycokeys.51.33513