The fish in the linked map are a visualization of colonial holdings in the nineteenth century. The text alludes to various baits and colonial catches, some of which have been landed and are in nets. John Bull, one of the personifications of England, already has a bounteous catch such as "Wei-Hai-Wei," a treaty port in China, and has hooked a Nile crocodile, symbolizing Egypt. Both the Tsar and the Kaiser also have their colonial fish such as Kiau-chau, better known as Tsingtao (the beer of the same name is not a coincidence, the Germans took their breweries abroad) and Port Arthur. This map is not above some of the hyperbole of other cariactature maps of this era; Nicholas II's catch are noticeably sharks instead of a more benign species of fish. There was considerable fear in the UK over Russian expansion at the turn of the century and the inset text notes possible perfidy in the Russian Empire's offer of an olive branch while casting lines in the Far East. The map also alludes to the US's recent gains in the Spanish-American War with Puerto Rico and Cuba being hooked while the Philippines are giving the angler a fight, a reference to the Philippine insurgency

This segues into Portugal's fish, labeled Delagoa. This was the Portuguese name for Maputo Bay in the southern portion of Mozambique. This slice of Africa was a Portuguese colony, but Portugal was a declining imperial power by the nineteenth century. There was considerable fear within Lisbon that the British would pry off Delagoa Bay from Portugal. There was considerable labor traffic between this Portuguese holding and the gold mines of the Transvaal. Additionally, there was an issue of a railway built along the Bay to the South African city of Pretoria.

Delagoa Bay was one of the few outlets available to the Transvaal to the Indian Ocean. There was a fear within the Portuguese colonial office that the British would seize this area on thin pretext. There were other interested parties in this corner of Africa as well. The Germans did finance some of the Portuguese rail-lines in this region. And Portugal did seize the railways in Delagoa in 1899, leading to a series of arbitration rulings between the UK and Portugal over the railways.

So the caption makes a bit more sense now. The hugged fish is an old catch of Portugal's, but one that has potential buyers. Portugal's Prime Minister Ernesto Hintze Ribeiro may be zealously guarding his fish, but there is the possibility he could sell it to other bidders. As the inset text quips, Portugal might sell its catch to its advantage, "whereby {Portugal's} empty purse may assume rounder proportions." So here, the cartoon is lampooning Portugal's declining status and desire to hold such status, a possible allusion to the railway seizures, but also noting the mercenary nature of this wherein a declining power could sell its possessions to the right bidder.