Correct identification and classification of sponges is challenging due to ambiguousor misleading morphological features. A particular case is a blue keratose spongeoccasionally referred to as the ... Show moreCorrect identification and classification of sponges is challenging due to ambiguousor misleading morphological features. A particular case is a blue keratose spongeoccasionally referred to as the ``Blue Photo Sponge'' among aquarists, which appearsfrequently (and in several cases unintended) in private aquaria. This spicule-less species,occasionally specified as Collospongia auris Bergquist, Cambie & Kernan 1990, not onlydisplays a high phenotypic plasticity in growth form and colour, it also proliferatesin aquacultures under standard conditions unlike most other sponges. Therefore, thisspecies is regarded as a pest for most aquarists. In turn, the ease of cultivation andpropagation in aquacultures qualifies this species as a model organism for a wide arrayof scientific applications. For these purposes, correct identification and classification areindispensable. We reconstructed ribosomal gene trees and determined this species asLendenfeldia chondrodes (De Laubenfels, 1954) (Phyllospongiinae), distant to Collospon-gia auris, and corroborated by skeletal features. Additionally, the resulting phylogenycorroborated major shortcomings of the current Phyllospongiinae classificationitsconsequences are discussed. Show less
Small, irregular isolated bones identified as remains of leatherback turtles (Dermochelys coriacea) were recovered from Mid to Late Holocene sites at Ra’s al-Hamra and Ra’s al-Hadd, coastal Oman.... Show moreSmall, irregular isolated bones identified as remains of leatherback turtles (Dermochelys coriacea) were recovered from Mid to Late Holocene sites at Ra’s al-Hamra and Ra’s al-Hadd, coastal Oman. These provide the third instance of this animal being documented from any prehistoric site anywhere, and the records provide one of the oldest, if not the oldest, dates for this distinctive chelonian—even though they do not refer to fossils. Decades of research in this region has yielded vast amounts of archeological information, including abundant evidence of intense exploitation and utilization of marine turtles from about 6,500 to 4,000 BP. During part of this period, turtle remains in human burials have been extraordinary; the turtle involved, Chelonia mydas, has been abundant in the region during modern times. Yet despite intense and varied forms of prehistoric marine resource exploitation, and major, long-term archeological work, no other turtle species has been previously authenticated from these, or other coastal sites. The documentation of remains of the largest and most distinctive of living marine turtles, D. coriacea, at Ra’s al-Hamra and Ra’s al-Hadd, presented herein, provide detailed information that serves as the basis for future interpretations and discussions regarding incomplete, disarticulated remains from the Mid to Late Holocene, particularly in reference to taphonomic questions and diverse environmental conditions. Show less
Relationships between phylogenetic relatedness, hybrid zone spatial structure, the amount of interspecific gene flow and population demography were investigated, with the newt genus Triturus as a... Show moreRelationships between phylogenetic relatedness, hybrid zone spatial structure, the amount of interspecific gene flow and population demography were investigated, with the newt genus Triturus as a model system. In earlier work, a bimodal hybrid zone of two distantly related species combined low interspecific gene flow with hybrid sterility and heterosis was documented. Apart from that, a suite of unimodal hybrid zones in closely related Triturus showed more or less extensive introgressive hybridization with no evidence for heterosis. We here report on population demography and interspecific gene flow in two Triturus species (T. macedonicus and T. ivanbureschi in Serbia). These are two that are moderately related, engage in a heterogeneous uni-/bimodal hybrid zone and hence represent an intermediate situation. This study used 13 diagnostic nuclear genetic markers in a population at the species contact zone. This showed that all individuals were hybrids, with no parentals detected. Age, size and longevity and the estimated growth curves are not exceeding that of the parental species, so that we conclude the absence of heterosis in T. macedonicus-T. ivanbureschi. Observations across the genus support the hypothesis that fertile hybrids allocate resources to reproduction and infertile hybrids allocate resources to growth. Several Triturus species hybrid zones not yet studied allow the testing of this hypothesis. Show less
Kraemer, M.; Huynh, Q.B.; Wieczorek, D.; Balliu, B.; Mikat, B.; Boehringer, S. 2018
