Evolution of mantis shrimp telson armour and its role in ritualized fighting

Mantis shrimp possess both formidable weapons and impact-resistant armour that clash during ritualized combat. The telson is one of few biological structures known to withstand the repeated high impact forces of smashing mantis shrimp strikes, and it is hypothesized that this pairing of armour and weapon is associated with the evolution of telson sparring. We carried out a comparative analysis of telson impact mechanics across 15 mantis shrimp species to assess if the telsons of sparring species (i) are consistently specialized for impact-resistance, (ii) are more impact-resistant than those of non-sparring species, and (iii) have impact parameters that correlate with body size, and thereby useful for assessment. Our data from ball drop tests show that the telsons of all species function like a stiff spring that dissipates most of the impact energy, but none of the measured impact parameters are correlated with the occurrence of sparring behaviour. Impact parameters were correlated with body mass for only some species, suggesting that it is not broadly useful for size assessment during ritualized fighting. Contrary to expectation, sparring mantis shrimp do not appear to have coevolved telson armour that is more robust to impact than non-sparring species. Rather, telson structure is inherently impact-resistant.

Causes, Manifestations and Nature of Indigenous Wars in Upper Bakweri Land, 1880-1939

The pursuit to control the villages of Upper Bakweri Land (UBL) by the villages of Soppo Mokongo (Great Soppo) and Gbea (Buea Town) led to a series of wars which erupted in the area between 1880 and 1939. The desire for domination resulted to the formation of two main groups which aligned the other villages of UBL under the leadership of either Soppo Mokongo or Gbea. The creation of competing blocs culminated to the upsurge of indigenous wars among the villages of UBL that dragged the two lead villages to support one side or the other. This paper examines the reasons for, the manifestation and the nature of indigenous wars in UBL between 1880 and 1939. To attain the goals of the paper, the chronological and thematic methods were employed in analyzing and synthesizing data obtained from primary and secondary sources. Information from primary sources came from the National Archives Buea (NAB) and oral interviews. Material gotten from secondary sources was from both published and unpublished works. The findings show that political, economic and socio-cultural factors were the driving force behind indigenous wars in the area. That ritualized combat, the cutting of the head of the leader illustrated the nature of warfare. That the weapons of war used were dane guns, cutlasses and clubs. Although, the wars were classified as either “just” or “unjust’; they never succeeded in establishing a lead village in UBL.