Cardiovascular system of anomuran crabs, genus Lopholithodes

Abstract

The cardiovascular systems of Puget Sound king crabs, Lopholithodes mandtii, and brown box crabs, Lopholithodes foraminatus, were mapped using corrosion casting techniques. Both species have a similar external morphology and a very similar cardiovascular system. Seven arteries (five arterial systems) arise from the heart. The small anterior aorta exits from the anterior surface of the heart and supplies hemolymph to the eyestalks and brain region. The pathway of the two sets of paired arteries, the anterolateral arteries and hepatic arteries, is close, and they intertwine with one another during their initial course. The anterolateral arteries exit from the anterior dorsal surface of the heart and supply hemolymph to the hypodermis, cardiac stomach, antennal gland, and mandibular muscles, whereas the hepatic arteries branch profusely within the hepatopancreas. The lithodids are believed to have evolved from hermit crab ancestors; indicative of these evolutionary origins the posterior aorta is well developed and supplies hemolymph to the large abdomen and the gonads. Exiting from the ventral surface of the heart, the sternal artery is the largest in the system. It branches to supply the mouthparts, chelae, and pereiopods. The differing arrangement of this vessel compared with that of the pagurid anomurans is due to the more carcinized (crab-like) morphological features of the lithodid anomurans. The arrangement of vessels supplying the gills is different compared with that of brachyuran crabs; the infrabranchial sinus joins to the afferent gill vessels at their midpoint, rather than along the ventral edge. In general, the circulatory system of the lithodid crabs is somewhat simpler than that of brachyuran crabs, with fewer branching capillary-like networks. Nevertheless, it is still very complex. In accordance with anatomical descriptions of blue crabs and cancrid crabs it would also seem appropriate to classify the lithodid circulatory system as one that is incompletely closed.

The anatomy of the king crab Hapalogaster mertensii Brandt, 1850 (Anomura: Paguroidea: Hapalogastridae) – new insights into the evolutionary transformation of hermit crabs into king crabs

“…The artery systems in the dorsal cephalothorax (anterior aorta, anterior lateral arteries and inferior lateral arteries) in Hapalogastridae exhibit the same pattern as in Lithodidae, which in turn closely resembles that found in Paguridae. The asymmetrical course of the pleonal arteries corresponds in pagurids and king crabs, likewise supporting the theory of a close relationship between both groups (for detailed descriptions of the hemolymph vascular system in Lithodidae (see McGaw andDuff, 2008 andKeiler et al, 2013; for Paguridae see Jackson, 1913 andKeiler et al, 2013). Remarkably enough, the sponge-like antennal bladder in Hapalo gaster corresponds to the bladder in Pagurus (see Jackson, 1913;pl.…”

Behavioural and respiratory response of the shallow-water hermit crab Pagurus cuanensis to hydrostatic pressure and temperature

“…The process of carcinization involves a long membranous abdomen becoming transformed into a reduced state, folded under the thorax and pressed against the sternum, negating the need for further protection of the abdomen from a gastropods shell or similar (McLaughlin and Lemaitre, 1997). Furthermore, this transition from hermit crabs to king crabs likely coincided with an increase in the abundance of the laminarid kelps (Saunders and Druehl, 1992;McGaw and Duff, 2008), which may have provided protection from predation and thus allowed the loss of the gastropod shell shelter. This hypothesis suggested the initial evolution of the soft-abdomen lithodids, followed by the fully carcinized subfamily Lithodinae (Zaklan, 2002;McGaw and Duff, 2008).…”

“…Furthermore, this transition from hermit crabs to king crabs likely coincided with an increase in the abundance of the laminarid kelps (Saunders and Druehl, 1992;McGaw and Duff, 2008), which may have provided protection from predation and thus allowed the loss of the gastropod shell shelter. This hypothesis suggested the initial evolution of the soft-abdomen lithodids, followed by the fully carcinized subfamily Lithodinae (Zaklan, 2002;McGaw and Duff, 2008). Cunningham et al (1992) assessed ribosomal RNA of both families and found close similarities between Pagurus and Lithodes species, placing the king crabs within the genus Pagurus, as well as estimating that the transition occurred between 13 and 25 million years ago.…”

Comparative morphology of the hemolymph vascular system in Uropygi and Amblypygi (Arachnida): Complex correspondences support Arachnopulmonata

“…Recent studies have demonstrated that vascular systems in certain arthropod taxa, such as certain Malacostraca (Sandemann, 1967;McGaw, 2005;McGaw and Duff, 2008;Wirkner and Richter, 2010;Huckstorf and Wirkner, 2011;Keiler et al, 2013Keiler et al, , 2015, certain Chilopoda (Wirkner and Pass, 2002) and also many Chelicerata (Wirkner and Prendini, 2007;Klußmann-Fricke et al, 2012Huckstorf et al, 2013;G€ opel and Wirkner, 2015) are highly complex. In some arachnopulmonate taxa, this level of complexity has been observed, not only in the hemolymph vascular systems (HVS) in general, but especially in the arte-rial systems of the prosomal ganglion.…”