Wittmann, Schlacher & Ariani 1993
Wittmann, Schlacher & Ariani 1993
WITTMANN, K. J., T. A. SCHLACHER & A. P. ARIANI, 1993: Structure of Recent and Fossil Mysid Statoliths (Crustacea, Mysidacea). Journal of Morphology, 215: 31-49.
https://doi.org/10.1002/jmor.1052150103
Statoliths of 61 Recent species representing all subfamilies of Mysidae were studied with special emphasis on internal structure. In addition 5 samples of fossil statoliths from Miocene deposits were examined. Species of Boreomysinae and Rhopalophthalminae show simple roughly spherical organic statoliths, with setae originating from the sensory cushion and anchored in the statolith with distal branches extending shortly below the surface. All other subfamilies possess mineralized statoliths of greater structural complexity, with differentiation in core and mantle, where each part may consist of up to three layers. Habitus is hemispherical to discoidal. External gross structures are dorsal tegmen, ventral fundus, and the ambitus forming the outer toroidal to semi-toroidal circumference. Setae penetrate the mantle through mineralic canals and insert on the surface of the core. As suggested by congeneric species of Schistomysis, there is no principal structural difference between statoliths mineralized with fluorite compared to vaterite. However, vaterite statoliths tend to be more often of moruloid appearance and are exceptional by showing a central conical hole (the hilum) or a central cavity in certain forms. These structures are typical of fossil calcite statoliths. In vaterite and fluorite statoliths, the mantle shows radially arranged (= spherulitic) crystal aggregates. Such arrangements are badly preserved in fossil calcite statoliths. In large extant statoliths, concentric structures, mainly in the form of superficial striation and/or concentric microstrata, are visible in coexistence with radial aggregates. Stratification is possibly due to stratified deposition of the nonmineralized gland product, while the spherulitic structure is indicative of subsequent radial growth of crystal aggregates. The structure of accessory fluorite statoliths in the statocyst of Mesopodopsis slabberi leads to the hypothesis that mantle material is formed by secretions of the caudal statocyst gland. After demineralization of fluorite, vaterite and calcite statoliths, an organic template remains showing most essential morphological features of the statolith. From this we conclude that the structure of the statolith is (almost) entirely matrix mediated.
Pontocaspian; Miocene; statolith; evolution; biomineralogy; palaeoecology; morphology; fluorite; vaterite; calcite
Acanthomysis longicornis; Amblyops abbreviata; Anchialina; Anchialina agilis; Anchialina oculata; Antarctomysis maxima; Antarctomysis ohlinii; Boreomysinae; Boreomysis; Boreomysis arctica; Boreomysis megalops; Boreomysis tridens; Dactylamblyops hodgsoni; Diamysis; Diamysis bahirensis; Diamysis pengoi; Erythropini; Erythrops elegans; Euchaetomera zurstrassen; Gastrosaccinae; Gastrosaccus; Gastrosaccus magnilobatus; Gastrosaccus mediterraneus; Gastrosaccus sanctus sanctus; Haplostylus; Haplostylus Heteromysis formosa; Heteromysis mayana; Holmesiella affinis; Leptomysini; Leptomysis buergii; Leptomysis lingvura adriatica; Leptomysis posidoniae; Limnomysis benedeni; Mesopodopsis slabberi; Mesopodopsis wooldridgei; Meterythrops microphthalma; Mysidae; Mysidella typica; Mysidellinae; Mysidetes sp.; Mysidium integrum; Mysidopsis bahia; Mysinae; Mysini; Mysis relicta; Neomysis integer; Neomysis japonica; Paraleptomysis banyulensis; Paramysis; Paramysis arenosa; Paramysis helleri; Paramysis kroyeri; Paramysis lacustris tanaitica; Paramysis pontica; Praunus flexuosus; Rhopalophthalminae; Rhopalophthalmus terranatalis; Sarmysis; Schistomysis assimilis; Schistomysis ornata; Schistomysis spiritus; Siriella aequiremis; Siriella anomala; Siriella armata; Siriella clausii; Siriella jaltensis gracilipes; Siriella longipes; Siriella pacifica; Siriella thompsonii; Siriellinae