Harald Ahnelt

Early development of the postcranial skeleton of the pikeperch Sander lucioperca (Teleostei: Percidae) relating to developmental stages and growth

The early development of the postcranial skeleton (pectoral girdle, pelvic girdle, vertebral column and fins) in pikeperch (Sander lucioperca (L.)) was studied from hatching to days 47 and 43 post fertilization (dpf) at two different rearing temperatures, 15.5 and 18.0°C. Four embryonic and six larval stages were described, ranging from 3.4 ± 0.3 mm to 21.8 ± 2.1 mm in total length. The crucial point in larval development is swimbladder inflation, which enables larvae to swim energy efficiently. Until this time point, only the most essential skeletal elements to enable swimming movements have developed. As the larvae become neutrally buoyant, they grow and differentiate postcranial elements rapidly. Concurrently, swimming performance and foraging success seems to improve. A specific size is correlated with a distinct developmental stage defined by a set of traits that includes the skeletal elements. The developmental sequence of skeletal structures is temperature independent, although growth is slower and the individual developmental stages are reached later at 15.5°C than at 18.0°C. J. Morphol. 2012.

Otoliths in situ from Sarmatian (Middle Miocene) fishes of the Paratethys. Part III: tales from the cradle of the Ponto-Caspian gobies

Articulated fossil fish skeletons with otoliths in situ provide a unique opportunity to link these two, otherwise independent data sets of skeletons and otoliths. They provide calibration points for otoliths also adding important information for the evolutionary interpretation of fishes. Here, we review nine articulated skeletons of gobies from the early Sarmatian of Dolje, Croatia, and Belgrade, Serbia, which were previously regarded as members of a single gobiid and a callionymid species. We found them to represent five different gobiid species belonging to five different genera, four of which are related to extant endemic Ponto-Caspian gobiid lineages. The species are: Aphia macrophthalma n.sp., Proneogobius n.gen. pullus (the only previously recognized species), Protobenthophilus n.gen. squamatus n.sp., Economidichthys triangularis (a species first described based on otoliths) and Hesperichthys n.gen. reductus n.sp. Five specimens contained otoliths in situ and a sixth shows imprints of otoliths which unfortunately must have been lost in the past, probably during preparation of the fossil. Together, they represent all five species recognized by skeletons, and three are linked to otolith-based species. Isolated otoliths have been reviewed from a variety of collections from Sarmatian strata in Austria, Bulgaria, Czechia, Romania and Slovakia resulting in the description of five new otolith-based species: Benthophilus? ovisulcus n.sp., Benthophilus styriacus n.sp., Protobenthophilus strashimirovi n.sp., Economidichthys altidorsalis n.sp. and Knipowitschia bulgarica n.sp. Our review demonstrates that all major endemic Ponto-Caspian gobiid lineages were already present during Sarmatian times, thereby pushing back their origin by approximately 5–10 myr in comparison to previously published dates for dichotomies. In our assessment, the origination of these lineages is linked to the early stage of separation of the Paratethys from the world oceans and the ecological changes that occurred during that time. These geological events parallel a dramatic increase in gobiid radiation and speciation, giving rise to many lineages, not all of which have persisted until today.

First record of the rare gobiid fish Gobius couchi in the Ligurian Sea (north-western Mediterranean)

The first record of Gobius couchi for the Ligurian Sea and the second record of this rare gobiid fish for the western Mediterranean are reported.

Gobiid fishes of the genera Chasar, Mesogobius and Neogobius (Teleostei: Gobiidae) from Iran (South Caspian Basin)

Abstract The neogobiine fishes Chasar bathybius, Mesogobius nonultimus, Neogobius caspius and Neogobius syrman are reported from the Caspian Basin of Iran. These four gobiid species are rarely found in the southern part of the Caspian Sea. In this study the first documented records of these species are presented for Iran.

The drift of early life stages of Percidae and Gobiidae (Pisces: Teleostei) in a free-flowing section of the Austrian Danube

The drift of early development stages is an essential element of dispersal in many fish species. It is caused by a multitude of factors and is thus highly specific for each taxon and developmental stage. In this paper, we examined the drift of free embryos, larvae, and juveniles of percids and gobiids in a free-flowing stretch of the Austrian Danube. We assessed the drift density (DD) at different distances from the shore, described seasonal and diel patterns, and how size of drifting fish changed throughout the season. The seasonal patterns as well as the DDs were highly specific for each genus, while the diel patterns and changes in size of drifting fishes differed primarily at family level. In addition, we compared two opposed shorelines—a near-natural gravel bar and a rip-rap stabilized shore. The shores differed significantly and on both shores the DD of gobies was higher compared to percids. Among the Gobiidae, the invasive Neogobius species clearly dominated (99% of total gobiid catch) over the native tubenose goby Proterorhinus semilunaris. Percid DD was substantially higher on the near-natural shore, with Zingel and Sander as the most abundant genera.

The complete mitochondrial DNA sequence of Pectenocypris sp. (Actinopterygii: Cyprinidae) from Serkap River, Sumatra, Indonesia

Abstract The whole mitochondrial genome of a small cyprinid freshwater fish Pectenocypris sp. collected from Serkap River, Central Sumatra, Indonesia was sequenced. This mitochondrial genome consisted of 16,589 bp and included 37 genes in the same order as in many other vertebrates including the human. Phylogenetic analysis suggested that this taxon clusters with Boraras maculatus among several Rasbora species.

Imprecise naming: the anadromous and the sea spawning threespine stickleback should be discriminated by names

Two ecological forms of the threespine stickleback Gasterosteus aculeatus – a strictly marine form and an anadromous form – are often merged in the literature as a single “marine” form. Because we know virtually nothing of the life style of the two oceanic ecotypes in the sea and consequently nothing on reproductive isolation and gene flow I argue for a precise use of the ecological terms “marine” and “anadromous” for these two ecotypes. These terms should be self-describing. The frequent use of terms incorrectly describing intraspecific variation and life style of ecotypes can bias studies on community composition and interactions of populations.

Translocations of tropical and subtropical marine fish species into the Mediterranean. A case study based on Siganus virgatus (Teleostei: Siganidae)

Abstract About 160 exotic fish species are documented from the Mediterranean Sea (MED). A relatively small but rapidly increasing percentage of these non-indigenous species is represented by tropical or subtropical fishes which are naturally not distributed in a sea adjacent to the MED. The occurrence of these species is mainly ascribed to shipping traffic and aquarium trade as they are not able to actively arrive at the MED via the Suez Canal or the Strait of Gibraltar. During a survey of siganid fishes at the Natural History Museum in Vienna, a single specimen of the Barhead spinefoot, Siganus virgatus that had been captured in 1975 in the Adriatic Sea was found. It represents the first record of this species for the MED. It is also one of the earliest confirmed records of the introduction of a tropical fish species into the MED and an example of a drastically translocated species (DTS). Nearly all records of drastically translocated fish species (DTFS) were just published this century, although one record dates back to the 19th century. A rapid increase of such translocations into the MED has been observed since 2010. The rising water temperatures caused by climate change increases the probability that such species will establish self-sustaining populations in the MED. A first compilation of DTFS into the MED is presented. Characters distinguishing S. virgatus from the closely related sister species S. doliatus, as well as from the Lessepsian migrants S. luridus and S. rivulatus, are given.

About the record of Salaria basilisca (Pisces: Blenniidae) in the Adriatic Sea, in 1874

The record in the northern Adriatic sea in 1874 of a specimen of the Salaria basilisca is discussed. The northernmost record for the Mediterranean area is confiremd by analysing the speciemn from the Natural History Museum of Vienna.