Decapod burrows in mangrove‐channel and back‐reef environments at the Atlantic barrier reef, Belize

Abstract

Burrows of decapod crustaceans were investigated by in situ resin casting in various mangrove and back-reef environments. Alpheid shrimps (A. floridanus and A. heterochaelis) were the most numerous burrowing shrimps in soft muddy sediments of mangrove channels. Their burrows consist either of a single U or a series of U's inhabited by a pair of shrimp or are Y-shaped and inhabited by a single shrimp and a gobiid associate. Large mounds and deep funnels are produced by the thalassinidean Glypturus acanthochirus, both in bare sediments of mangrove channels and in back-reef subtidal sediments. Their burrows consist of a spiral with several radiating branches leading to the surface and deeper blind chambers often filled with shell particles reaching to a depth of over 160 cm. The thalassinidean Neocallichirus grandimana inhabits the intertidal of protected back-reef sands; it occupies shallow, mainly horizontal burrows. Corallianassa longiventris, characteristic of coarse sediments of the intertidal and shallow subtidal back-reef, inhabits simple J-to U-shaped burrows with blindly ending chambers in 60 to 80 cm sediment depth. Axiopsis serratifrons lives in pairs in sediments with a higher content of coral rubble; its burrows are simple, inclined, and spiral-shaped and reach a sediment depth of 30 cm.All burrows described in this paper are similar to those previously recorded for the respective species. Only the burrows of alpheids are less deep than those described from the intertidal. The burrowing activity of G. acanthochirus greatly influences grain size distribution and accumulation of large shell particles in deeper sediment layers. Burrow types reflect the systematic group to which the animals belong rather than feeding modes.

Geologic age and depositional environments of the uppermost part of the Middle Miocene Iriomote Formation in the Iriomote-jima Island, Okinawa, southwest Japan

“…Yaeyama Coalbearing Beds William and Warren 1960Saito et al, 1973, 1982;, 1982, Hanzawa, 1935, 1982, Nohara, 1971, 1986;, 1993;, 2001, Saitoh and Masuda, 20041 2 3 3 , 1982, 1989, 2001, 1982, 2000, Fig. 1B 700 m , 1964, 1982;Masuda and Sato, 1988 ;, 1982 , (Fig.…”

Rosarichnoides sudeticus igen. et isp. nov. and associated fossils from the Coniacian of the North Sudetic Synclinorium (SW Poland)

“…Though the po si tion of the spec i men stud ied is un known, it is not ex cluded that it was ver ti cally ori ented. The Griffis and Suchanek (1991) gen er al ized model was crit i cized by some authors (Dworschak and Ott, 1993;Nickell and Atkinson, 1995;Gibert and Ekdale, 2010;Hyžný et al, 2015) due to some features, such as the lack of mounds at the open ings and num ber of open ings in the fos sil re cord and the dif fi culty of as sign ing cer tain spe cies to a bur row type.…”

The aquatic Environment of Twin Cays, Belize

“…Fine-grained sand and carbonate mud. Median grain diameter of the sand fraction has a range of 94-268 pm, the mud fkaction (<63 pm) is 17-33% and the organic content 5.4-9.7% (Dworschak and Ott, 1993). The mud fraction tends to become resuspended during high winds, causing high turbidity.…”

“…Sediment. Medium-grained sand-size fraction (267-426 pm median diameters), with mud-size (<63 pm) fraction 9-21%, organic content 3.9-4.6% (Dworschak and Ott, 1993).…”

“…Fine calcareous sand and mud, that is, rich in organics, make up the bottom of the Main and Lair channels and support stands of seagrass (Thalassia, Halodule) and algae (Halimeda, Penicillus, A vrainvillea), large populations of upside-down jelly fish (Cassiopea), and an ubiquitous burrowing crustacean endofauna that forms characteristic mounds, deposits from its tunneling activity (Dworschak and Ott, 1993). Despite the plant cover and consolidation by mucuous substances derived from bacteria, cyanobacterial mats, fecal pellets, and other sources, the sediment is easily disturbed and resuspended by storms, manatee feeding, and boat traffic.…”