Gerald Hugh Jennings  

 This is the home page of Gerald Jennings, founder of the Calypso  Environmental Group of businesses


         Useful Links

The Calypso Organization

Calypso Publications

Calypso Online Fish Bookshop

Calypso Ichthyological Database


Kraken logo

Hillness Research

Hillness Research Foundation logo

Marine Biological Association

British Standards Institute

Calypso Landscapes




Aquarists Reunited


IMSS logo

Linked In - Oceanography group

The Calypso Group of businesses started out in 1979 with the founding of Calypso Publications, a specialist ichthyological and marine biological publishing house. Calypso Publications has to date published over 100 specialist books and technical papers specifically relating to marine biology and related aquatic subjects. The group now comprises many related offshoots, the largest of which is  the Calypso Online Fish Bookshop which carries well over 1,000 specialist aquatic and ichthyological titles in stock, and has a print-on-demand service for rare and older publications. 

Prior to Calypso, Gerald was educated at William Ellis Grammar School and then at the Marine Biological Association of the United Kingdom at Plymouth, and the then newly formed Open University. While working with Anthony Evans on PetFish monthly magazine, he  was one of the co-founders of the Marine Study Aquatic Society  ( later to become the International Marine Study Society , of which he was later awarded a fellowship) and then went on to also become a co-founder of the marine biological supply house, Kraken , who formulated the first modern synthetic seasalt mix for laboratory use, followed by an appointment as Research Director of the Hillness Research Foundation   in both London and Malta before spending some time with the British Standards Institute in the mid-seventies prior to founding Calypso Publications in 1979

I was one of the promoters involved in the development of the Calypso Ichthyological Database  in 1994 which  is a system allocating a unique database number to every fish species, which does not change ,(as the taxonomic name  can over time.)  Every species is allocated a unique six digit number which also indicates in the numbering the distribution and family relationships of the species concerned.

In 2001 I  was asked to act as the European Secretary for IFOCAS, the International Federation of Online Clubs and Aquatic Societies, and as part of this project he set up the Aquarists Reunited  online web site

I still take an  active role in Calypso but is now semi-retired. He is married and lives in London.

In recent years Calypso have branched out into environmental garden construction and design and have developed an expertise in planning and constructing town gardens in  the North London area and since 2001 have  developed close ties with the fish rehoming service, Fishorphans.

I have also maintained a lifelong interest in Reliant motor vehicles, both three and four wheeled ,and have owned many over the past few decades. The Reliant motor company closed permanently in 2002 but  I still own a couple of the more unusual models.

Reliant Fox Van 1982   and Reliant Kitten Saloon 1976

Calypso's Mission

To increase the knowledge available to all on every aspect of Ichthyology, Oceanography, Marine husbandry and conservation, and care of captive aquarium livestock.To encourage environmental consciousness.

Contact Information

+44 207281 4948
+44 207281 4948
Postal address
2 Gatcombe Road, London N.194PT U.K.
Electronic mail
General Information:

Books by Gerald Jennings published by Calypso Publications


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Synthetic Seawaters for Aquaria and laboratoiries by Calypso    Maltese fishes and Fishes of Malta     Mediterranean Fishes A dodecalingual index Gerald Jennings

The sea and freshwater fishes of Australia North           The sea and freswater fishes of Australia South and Tasmania

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Copyright ? 2019/2020 Calypso Group
Last modified 10/12/2019