Seasonal and diel changes in the structure of a crustacean decapod assemblage associated to a shallow Cymodocea nodosa meadow in northern Tunisia (Mediterranean Sea). An overview of the Mediterranean decapod taxocoenoses.

A study on the decapod assemblage inhabiting a shallow meadow of Cymodocea nodosa from the bay of La Goulette (Tunisia) was carried from February 2009 to February 2010. Monthly samples (with replicates) were taken in the morning and at night, with a small Agassiz trawl. In total 11699 specimens belonging to 41 species were caught. Significant day-night and seasonal changes are mainly related to movements (feeding) and recruitments. Higher abundance and richness were reported at night. Analyses rendered no significant relationships between the plant phenology and abundances and richness; neither between the total abundance and temperature, but significant correlations with a time lag of 3 - 4 months between these factors exist, which could be related with hatching and larval development period. The nocturnal and diurnal values in the diversity and equitability indexes are quite similar along the year (peaks in spring - early summer, minimum in autumn - early winter). This pattern is mainly due to the strong dominance of a few species, with maximum abundances during their recruitment events, whose seasonal and day-night changes have been determined. Besides, an overview of the decapods assemblage associated to this seagrass for the Mediterranean Sea has been carried out. The species can be divided into two groups (linked to the leaves and to the sediment). The differences in species composition between areas must be related to different sampling methodologies, feeding and reproductive strategies, but also to the layout and influence of the surrounding habitats

One hundred years after Pinctada: an update on alien Mollusca in Tunisia

The occurrences of non-indigenous marine molluscs in Tunisia are reviewed, based booth on a literature survey and on original material. Species are accepted as established if there are two independent reports, either geographically separate or at least one month apart in time. On these grounds, 14 species are accepted (12 alien and 2 expanding their range from elsewhere in the Mediterranean), 3 aliens need confirmation but are likely to meet the standards for acceptation on a short future, and 5 records are rebutted or questioned. Two more species may be considered as cryptogenic, the reports are reliable but it is not clear indication that they are not indigenous. Two of the alien species are reported for the first time in Tunisian waters: the nudibranch Polycerella emertoni qualifies as established, and the bivalve Anadara transversa is tentatively identified from a juvenile live-taken specimen, which awaits further confirmation. The occurrence of aliens in Tunisia is balanced between presumably Lessepsian species of tropical Indo-Pacific origin, and species from other sources including species from the Tropical Atlantic introduced through shipping. Nevertheless there is a prevalence of Lessepsian species towards the Gulf of Gabes in the south, whereas the shipping activity in Tunis harbour may be the main pathway of introduction in the north

A new species of Flabelligeridae (Annelida), Trophoniella radesiensis n. sp., from Tunisia

Este artículo contiene 11 páginas, 6 figuras, 1 tabla.The family Flabelligeridae was previously represented in Tunisia by four genera including four species: Bradabyssa villosa (Rathke, 1843), Therochaeta flabellata (M. Sars in G.O. Sars, 1872), Pherusa plumosa (Müller, 1776), and Piromis eruca (Claparède, 1869). In this paper we report a fifth genus, Trophoniella, for the first time in Tunisia. The specimens were collected in Radés Station, Gulf of Tunis (Central Mediterranean) and belong to a new species, namely Trophoniella radesiensis n. sp., which is characterized by having: (1) a very smooth tunic, body covered dorsally, ventrally, and laterally by sediment grains (except in the posterior region), and (2) well-developed parapodia showing short neurohooks from chaetiger 6 to 19 and anchylosed neurohooks from chaetiger 20. Based on the 16S, the new species belongs to a low supported Piromis/Trophoniella clade and shows a 16.1% of genetic distance from Trophoniella hephaistos Jimi & Fujiwara, 2016, the single known species of the genus sequenced to date. [Zoobank lsid: urn:lsid:zoobank.org:act:D7C85C70-87FF- 4AF4-8599-A8462B3FB8B1]Funds for this research were provided by the Tunisian Ministry of Higher Education, in collaboration with the Catholic University of the West, Angers.This paper is a contribution of Daniel Martin to the Consolidated Research Group on Marine Benthic Ecology of the Generalitat de Catalunya (2017SGR378) and to the Research Project PopCOmics (CTM2017-88080), funded by the “Ministerio de Ciencia, Innovación y Universidades” of Spain (MICINU), the “Agencia Española de Investigación” (AEI) and the European Funds for Regional Development (FEDER).Peer reviewe

Trophoniella radesiensis Chaibi & Antit & Bouhedi & Meca & Gillet & Azzouna & Martin 2019, n. sp.

Trophoniella radesiensis n. sp. Chaibi and Gillet Figures 3–6 urn:lsid:zoobank.org:act: D7C85C70-87FF-4AF4-8599-A8462B3FB8B1 Material examined. Holotype: MNCN16.01 /18453, collected on 25 Nov 2015 in Radés Station, Gulf of Tunis (15°55′ N, 97°41′ W) by the first author. Paratypes: MNCN 16.01 /18454. 6 specimens, same data as for holotype; UCO T FLA 025.1specimen, same data as for holotype. Diagnosis. Body covered by sediments of different grain size (50–1000 µm of long axe) embedded on tunic, completely concealed except in posterior region. Tunic pale, dorsally smooth, ventrally rough, with large papillae, carrying sediment grains and particles. Body papillae arranged in two dorsal and four ventral rows. Branchial plate tongue-shaped. Unidentate anchylosed neurohooks from chaetiger 20. Description. Holotype with some chaetae broken, non-reproductive adult, unknown sex. 35 mm long, 4 mm wide, with 60 chaetigers; paratypes varying from 30–43 mm long and 1–4 mm wide for 43–74 chaetigers (Fig. 3 A– E). Anterior body sub-cylindrical in cross-section, tapering towards pygidium. Tunic transparent, dorsally smooth, ventrally rough with large papillae, carrying sediment grains and particles with long axes ranging from 50 to 1000 µm, totally embedded in tunic, completely concealing it dorsally and ventrally, absent in posterior region. Pale brown, slightly reddish anteriorly. Cephalic cage 12 mm long, with chaetae ca. 1.5 times longer than body width, formed by chaetigers 1–5; chaetiger 2 dorsolateral, chaetiger 3–4 lateral. Chaetal transition from cephalic cage to body chaetae gradual (Fig. 3A, 3 C–E). Body papillae similar in colour to body wall, mostly eroded, arising in two dorsal and four ventral longitudinal rows from first chaetiger to posterior end, better preserved anterior-most body region (Fig. 3A, 3 C–E). Parapodia well developed. Noto and neuropodia have four prechaetal papillae and five postchaetal papillae (Fig. 3C). Especially long papillae absent from anterior chaetigers. Gonopodial papillae not seen. Chaetiger 1 with about six notochaetae and eight neurochaetae; anterior dorsal margin with dorsal papillae, arising as a multifid cephalic veil (Fig. 4A). Chaetiger 5 widening posteriorly. Cephalic hood not exposed. Caruncle short and triangular (Fig. 4C, 4D). Branchiae cirriform, arising from tongue-shaped branchial plate, arranged in two lateral lobes (Fig. 4A, 4D), thin, long (0.5–3mm), whitish once preserved in ethanol, with ca. 60 filaments. Palp, long, corrugated, pale, as long as largest branchiae, 6 mm long (Fig. 4B, 4C). Prostomium lowcone, with two large and two small black eyes (Fig. 3D, 3E). Lateral lip expanded; dorsal and ventral lips not well developed (Fig. 3D, 3E). Notochaetae all multiarticulated capillaries; articles progressively longer towards falcate tips; medial ones in short longitudinal series, 4–7 per bundle; some yellowish some dark brown; unidentate tips (Fig. 5 A–5D). Multiarticulated capillary neurochaeta from chaetiger 2 to 5, then short unidentate neurohooks from chaetiger 6 to 19 (Fig. 6A) and anchylosed hooks from chaetiger 20 to body end (Fig. 6B), darker than preceding ones, arranged in transverse series of 4–6 units per bundle, similarly wide along their length, subdistally not or slightly expanded, with short rings continued up to a subdistal, non-annulated hyaline region, hooked, tapering to roughly pointed, unidentate tips (Fig. 5A, 6B). Pygidium simple, with single anal cirrus. No intra-specific variability in morphological characters was observed, except for lacking sediment gains in some specimens. Distribution. Known only from the type locality, Radés Station (Gulf of Tunisia, Mediterranean Sea). Collected from both soft and rocky bottoms, from 3–4 m to 10 m depth. Etymology. The species name radesiensis refers to the type locality, Radés Station.Published as part of Chaibi, Marwa, Antit, Mouna, Bouhedi, Marwa, Meca, Miguel A., Gillet, Patrick, Azzouna, Atf & Martin, Daniel, 2019, A new species of Flabelligeridae (Annelida), Trophoniella radesiensis n. sp., from Tunisia, pp. 551-561 in Zootaxa 4571 (4) on pages 554-556, DOI: 10.11646/zootaxa.4571.4.7, http://zenodo.org/record/261426

Trophoniella Hartman 1959

Key to the northern African and Mediterranean Sea species of Trophoniella 1. Anchylosed neurohooks first appearing on chaetigers 4–7.................................. T. incerta (Augener, 1918) - Anchylosed neurohooks first appearing on chaetiger 14 or posterior.............................................. 2 2. Tunic without sediment grains.................................................. T. fernandensis (Augener, 1918) - Tunic with sediment grains on both dorsal and ventral surfaces.................................................. 3 3. Sediment grains large, completely concealing the tunic............................ T. enigmatica Salazar-Vallejo, 2012 - Sediment grains varying in size, often small, not completely concealing the tunic................................... 4 4. Anterior chaetigers with notopodial lobes lacking papillae; first short neurohooks from chaetiger 10; anchylosed neurohooks from chaetiger 40............................................................. T. fauveli Salazar-Vallejo, 2012 - Anterior chaetigers with notopodial lobes carrying dorsal papillae; first short neurohooks from chaetiger 6; anchylosed neurohooks from chaetiger 20................................................................. T. radesiensis n. sp.Published as part of Chaibi, Marwa, Antit, Mouna, Bouhedi, Marwa, Meca, Miguel A., Gillet, Patrick, Azzouna, Atf & Martin, Daniel, 2019, A new species of Flabelligeridae (Annelida), Trophoniella radesiensis n. sp., from Tunisia, pp. 551-561 in Zootaxa 4571 (4) on page 559, DOI: 10.11646/zootaxa.4571.4.7, http://zenodo.org/record/261426