Multiple transgressions and slow evolution shape the phylogeographic pattern of the blind cave-dwelling shrimp Typhlocaris

Background: Aquatic subterranean species often exhibit disjunct distributions, with high level of endemism and small range, shaped by vicariance, limited dispersal, and evolutionary rates. We studied the disjunct biogeographic patterns of an endangered blind cave shrimp, Typhlocaris, and identified the geological and evolutionary processes that have shaped its divergence pattern. Methods: We collected Typlocaris specimens of three species ( T. galilea, T. ayyaloni, and T. salentina), originating from subterranean groundwater caves by the Mediterranean Sea, and used three mitochondrial genes (12S, 16S, cytochrome oxygnese subunit 1 (COI)) and four nuclear genes (18S, 28S, internal transcribed spacer, Histon 3) to infer their phylogenetic relationships. Using the radiometric dating of a geological formation (Bira) as a calibration node, we estimated the divergence times of the Typhlocaris species and the molecular evolution rates. Results: The multi-locus ML/Bayesian trees of the concatenated seven gene sequences showed that T. salentina (Italy) and T. ayyaloni (Israel) are sister species, both sister to T. galilea (Israel). The divergence time of T. ayyaloni and T. salentina from T. galilea was 7.0 Ma based on Bira calibration. The divergence time of T. ayyaloni from T. salentina was 5.7 (4.4-6.9) Ma according to COI, and 5.8 (3.5-7.2) Ma according to 16S. The computed interspecific evolutionary rates were 0.0077 substitutions/Myr for COI, and 0.0046 substitutions/Myr for 16S. Discussion: Two consecutive vicariant events have shaped the phylogeographic patterns of Typhlocaris species. First, T. galilea was tectonically isolated from its siblings in the Mediterranean Sea by the arching uplift of the central mountain range of Israel ca. seven Ma. Secondly, T. ayyaloni and T. salentina were stranded and separated by a marine transgression ca. six Ma, occurring just before the Messinian Salinity Crisis. Our estimated molecular evolution rates were in one order of magnitude lower than the rates of closely related crustaceans, as well as of other stygobiont species. We suggest that this slow evolution reflects the ecological conditions prevailing in the highly isolated subterranean water bodies inhabited by Typhlocaris

Pyrgospongia Achituv & Simon-Blecher, 2006, gen. nov.

Pyrgospongia gen. nov. Diagnosis: Wall concrescent, thin, made of radiating rods connected by chitinous material, elliptical in outline; ribs on shell absent; heath absent. Basis membranous. Scutum and tergum not fused, scutum transversally elongated, tergum triangular. Type species: Pyrgopsella stellula Rosell, 1973. Etymology: From the Greek pyrgos (tower), found in the family name Pyrgomatidae of the coral­inhabiting barnacles, and the Latin (from Greek) spongia (sponge), referring to the host group. Remarks: Based on the morphology of the shell and the opercular valves, Ross & Newman (1973) suggested that Pyrgopsella annandalei is an offshot of the “ Savignium line” of pyrgomatids. Anderson (1992) suggested that P. annandalei is a specialized member of the line of Savignium crenatum (Sowerby). However, the opercular valves of our material, as well of the material depicted by Gruvel (1907), are closer in form to those of Trevathana dentata (Darwin); a tergal tooth and a thin, pointed, inward­projecting tooth located on the spur are characteristic of T. dentata but missing in Savignium crenatum. The position of Pyrgospongia is more ambiguous. The opercular valves, elongated scutum, and especially the tergum of Pyrgospongia stellula, without any sign of an internal tooth, appear to be more similar to those of a different pyrgomatid line comprising those species of Cantellius with transversally elongated scuta, such as C. brevitergum (Hiro) or C. transversalis (Nilsson­Cantell). It might be supposed that Pyrgospongia was derived from within Cantellius. On the other hand, being a sponge­inhabiting rather than coralinhabiting barnacle and having rather pleisomorphic opercular valves, the Philippine and Japanese P. stellula may not be a pyrgomatid at all. Molecular analysis using DNA sequences may shed light on this enigma.Published as part of Achituv, Yair & Simon-Blecher, Noa, 2006, Pyrgopsella (Cirripedia: Balanomorpha: Pyrgomatidae) is not a sponge­inhabiting barnacle, pp. 29-42 in Zootaxa 1319 on page 39, DOI: 10.5281/zenodo.27355

Pyrgopsella Zullo 1867

Pyrgopsella Zullo 1867 Pyrgopsis Gruvel 1907 Pyrgopsella Zullo 1967 Diagnosis: Walls sub­conical, totally concrescent. Basis membranous with short peduncle. Opercular plates separate, scutum transversally elongated, tergum triangular. Type species: Pyrgopsella annandalei Gruvel 1907.Published as part of Achituv, Yair & Simon-Blecher, Noa, 2006, Pyrgopsella (Cirripedia: Balanomorpha: Pyrgomatidae) is not a sponge­inhabiting barnacle, pp. 29-42 in Zootaxa 1319 on page 31, DOI: 10.5281/zenodo.27355

Pyrgopsella youngi Achituv & Simon-Blecher, 2006, sp. nov.

Pyrgopsella youngi sp. nov. Achituv (Figs 1–6) Material examined: Fifteen specimens, six with soft parts, were obtained from a partly bleached colony of Symphyllia radians Milne­Edwards and Haime, found in a tropical fish shop in Israel. The source of the coral was Sulawesi, Indonesia, exact location unknown. The barnacles were suspended in the coral tissue and easily detached from the coral. Part of the host coral (catalogue number RMNH Coel. 33023) and the barnacle holotype (RMNH C. 2602: two slides with cirri and mouth parts, SEM stubs of shell and opercular valves) and two paratypes (RMNH C 2603 and RMNH C 2604: shell and opercular valves, and SEM stubs with shell and opercular valves, respectively) have been deposited in the RMNH. The other part of the host coral (catalogue number TAU Co 32349), the remaining paratypes, shell and opercular valves of four specimens prepared for SEM analysis, slides of two specimens with cirri and mouth parts, are deposited in the TAU (catalogue number TAU Ar 27804). Two specimens were used for DNA extraction. Etymology: The specific epithet honors the late Paulo Young in recognition of his contribution to our knowledge of cirripede biology. Diagnosis: Wall concrescent, ribs on shell absent. Basis, membranous, with inferior end calcareous. Scutum and tergum not fused, scutum transversally elongated, tergum triangular with internally directed tooth. Description: Shell (Fig. 1 C, 2 A, 3 A, B) white but nearly transparent, concrescent, low­conical, thin, oval, maximum carino­rostral diameter 8 mm, maximum lateral diameter 4 mm. Radiating rib absent; shallow, concentric growth lines on outer surface. Shell tubiferous, tubes wide, penetrating 2 / 3 of shell; inner shell white; sheath with concentric growth lines, reaching margins of shell; short spines on sheath perimeter located at margins of lateral septa, number of spines equal to number of septa, with no denticulation on margins of septa. Orifice oval, located at carinal end of shell; carinorostral diameter 1 / 3 carino­rostral diameter. Tergoscutal flaps banded purple on white cream ground. Basis (Fig. 1 B) membranous, sometimes with basal part elongated and peduncle­like, basal tip connected to small, white, calcareous disc, latter usually attached to septum of coral calyx (Fig. 3 A,B). Scutum and tergum white, separate. Scutum (Fig. 2 C, E) transversally elongated, thin, total length (including tergal tooth) ~five times maximal width; basal margins slightly sinusoidal; adductor muscle pit shallow, distinct; adductor ridge small, low; lateral depressor muscle pit indistinct; width of tergal tooth ~ 1 / 2 width tergal margin, located closer to occuludent margin then to basal margin; growth lines on outer surface; narrow, oblique furrow beginning at tergal margin halfway between tergal tooth and occludent margin, ending near occludent basal angle. Tergum (Fig. 2 D, F) triangular, growth lines on outer surface; short, spur barely distinct; external groove running from middle of scutal margin to basi­carinal apex; small notch in middle of scutal margin; basi­scutal angle pointed; thin, pointed, inward­projecting tooth on spur; notch in middle of carinal margin; inner side with depression accommoding tergal tooth of scutum; growth lines visible inside depression. Labrum (Fig. 4 A, E) rounded with deep median notch, very short, fine setae on margins and outer surface; palps (Fig. 4 A) elongate, oval with upper margins straight, long setae on outer surface, longest at distal end, inner margins with shorter setae. Mandible (Fig. 4 C) with five teeth along cutting edge, distances between teeth unequal, upper two teeth occupying 1 / 2 length cutting edge, second and fourth teeth bifid, lower angle with short spines; face and margins of mandible bearing setae, lower margins with combs, conical spines on lower angle. Maxillule (Fig. 4 D) with cutting edge unnotched, armed with row of ~ten unequal spines, tuft of smaller, hair­like setae at distal angle; setae scattered along upper part of maxillule, row of dense setae on lower part; some combs of hairs on face of maxillule projecting beyond cutting edge. Maxilla (Fig. 4 B) oval­elongate, long setae distally, short setae on inner side, few simple setae on upper and lower margins, distal surface with two rows of short, sharp setae; lower angle with two to three spines. Number of articles of cirri of three randomly selected individuals given in Table 1. Cirrus I (Fig. 5 A) highly setose; anterior ramus ~twice length of posterior ramus; proximal articles of anterior ramus and all segments of posterior ramus with protuberances bearing setae. Cirrus II (Fig. 5 B) with rami ~equal length; articles slightly protuberant, bearing long setae. Cirrus III with anterior ramus somewhat longer than posterior ramus; articles with protuberances bearing tufts of long, plumose setae (Fig. 5 C). Cirri IV (Fig. 5 D) to VI (Fig. 6 A) long and slender; each article with four pairs of setae of different lengths arranged along anterior margin, generally each pair accompanied by short, proximal seta; setae at distal end of articles longer, ~three times article width; two or three short setae at posterior articulation of each article (Fig. 6 B); basal articles with a row of pairs of setae. Penis (Fig. 6 A) long, annulated, scattered thin setae along length; distal end modified, more slender then rest of penis, not annulated, few setae (Fig. 6 C). Remarks: The barnacles from Symphyllia radians differ from those described by Gruvel (1907) in two striking aspects: the tergum as depicted and described by Gruvel carries a truncate internal tooth, whereas the inward projecting tooth found in our specimens is thin and pointed and located on the short spur. The second difference concerns the distal end of the penis. In Pyrgopsella annandalei it is ornamented with short spines, which are missing in our material, and the modified end of the penis in Gruvel’s material is pear­like, while in the present material this part of the penis is elongate. On the basis of these differences, we conclude that our material is not referable to P. annandalei, but should be assigned to a new species, named by us as P. youngi. In most coral­barnacles the shell is overgrown by the coral and calcareous material is deposited on the barnacle surface. In many cases the coral forms spines or perturbations over the surface of the shell plates and in some cases even an entire corallite. However, in Pyrgopsella, soft coral tissue covers the shell with no deposition of calcareous material over it and the barnacle comes to be suspended in the coral tissue. A more remarkable difference between Pyrgopsella and other pyrgomatids is the membranous basis with a vestigial, calcareous part. In all other coral­inhabiting barnacles the basis is calcareous and, in most cases, it is cone­like and tapered, embedded in the coral skeleton. A particular feature of the coral Symphyllia radians is the thick, fleshy tissue in which the barnacles are embedded. This thick tissue supports the barnacles, thus making a calcareous basis superfluous. Rosell (1973; 1975) reported the existence of a barnacle similar to Pyrgopsella annandalei embedded in a sponge collected in the Philippines. He described this barnacle as a new species, P. stellula. Grygier (1992) reported the occurrence of P. stellula in Japan, extending the geographical distribution of this species, and noted an additional species of Pyrgopsella in a sponge from Indonesia. Rosell (1973; 1975) suggested that the genus Pyrgopsella consists of sponge inhabiting barnacles and assumed that the host of P. annandalei was also a sponge. This view has been widely accepted, but our new find suggests that Pyrgopsella is a coral­barnacle and that Gruvel’s species, which is similar to ours, most probably was detached somehow from a coral. It is surprising that for a century, ever since its description by Gruvel (1907), Pyrgopsella was never reported from corals. Both P. annandalei and P. youngi are rather large pyrgomatids, reaching a carino­rostral diameter of 8 mm, and can hardly be missed. The lack of records until now can be explained by the way in which coral­inhabiting barnacles are studied. Mostly, the barnacles are extracted from dry corals kept in museum collections. Moreover, since identification of corals is based on the structure of the calices and septa, in many cases biologists remove the coral tissue using household bleach or an alkali solution, whereby Pyrgopsella with its membranous basis would be lost. Examination of the dried and bleached skeleton of the coral from which the present sample was removed showed no conspicuous evidence of the presence of the barnacles. Only detection of the vestigial calcareous basis could show that barnacles had formerly lived on the coral. In the collection of Naturalis, Leiden, there is a colony of Symphyllia radiance from S.W. Sulawesi (RMNH Coel 24745) with vestigial calcareous basis. Our new findings underline the importance of examining live corals, or corals preserved with their tissue, for the presence of barnacles, a technique that might reveal additional kinds of coral­inhabiting barnacle. The main feature that Pyrgopsella stellula (Figs. 1 C; 7 A, B), P. annandalei (Pl. 2 Fig. 7 b in Gruvel, 1907) and P. youngi (Fig. 2 A, B) share is a single­plate shell, but otherwise it is difficult to accept that these species all belong to the same genus. In addition to being symbionts of hosts from different phyla, there are striking morphological differences between these species. Pyrgopsella stellula lacks the peduncle that is present in P. annandalei (Pl. 2 Fig. 7 a in Gruvel, 1907) and in P. youngi (Fig. 1 B, D). In our material, and one may perhaps assume also in P. annandalei, the basal tip of the peduncle anchors the barnacle to the septa of a coral calyx. The shell of P. stellula is thin and flexible and only partly calcified (Fig. 7 A, B) The calcareous area is in the form of thin spokes radiating from the operculum and a flexible membrane connects those spokes. In P. youngi and P. annandalei, the shell is totally calcified. In P. stellula there is no distinct sheath, whereas it is distinct in P. annandalei and P. youngi (Fig. 2 B). The sickle­shaped, barbed bristles and star­like spines (Fig. 7 G) that are arranged in concentric rows over the outer shell membrane in P. stellula are absent in P. youngi. The shape of the opercular valves of P. stellula (Fig. 7 C, D, E, F) and those of P. annandalei (Pl. 2 Figs 9,10 in Gruvel, 1907) and P. youngi (Fig. 2 C, D, E, F) are different. The scutum of P. stellula is elongated, rather big and lacks a tergal tooth (Fig. 7 D); in situ it projects beyond the rostral margins of the shell (Fig. 1 D; see also Rosell 1975: Fig. 2 c). The tergum is missing the internal tooth that is found in the other species of Pyrgopsella (Figs 2 D, 7 C). Cirrus III of P. stellula carries small conical spines that are not found in P. youngi and cirrus IV of P. stellula is armed with diagonally arranged conical spines (Rosell 1975: Fig. 2 n) that are absent in P. youngi. On the basis of these differences we suggest that P. youngi sp. nov. and P. annandalei do not share the same evolutionary line as P. stellula and that the latter should be assigned to a different genus. Therefore, we propose a new genus, Pyrgospongia, to accommodate the sponge­inhabiting pyrgomatid Pyrgospongia stellula (Rosell 1973).Published as part of Achituv, Yair & Simon-Blecher, Noa, 2006, Pyrgopsella (Cirripedia: Balanomorpha: Pyrgomatidae) is not a sponge­inhabiting barnacle, pp. 29-42 in Zootaxa 1319 on pages 32-38, DOI: 10.5281/zenodo.27355

A star is torn—molecular analysis divides the Mediterranean population of Poli’s stellate barnacle, Chthamalus stellatus (Cirripedia, Chtamalidae)

Poli’s stellate barnacle, Chthamalus stellatus Poli, populates the Mediterranean Sea, the North-Eastern Atlantic coasts, and the offshore Eastern Atlantic islands. Previous studies have found apparent genetic differences between the Atlantic and the Mediterranean populations of C. stellatus, suggesting possible geological and oceanographic explanations for these differences. We have studied the genetic diversity of 14 populations spanning from the Eastern Atlantic to the Eastern Mediterranean, using two nuclear genes sequences revealing a total of 63 polymorphic sites. Both genotype-based, haplotype-based and the novel SNP distribution population-based methods have found that these populations represent a geographic cline along the west to east localities. The differences in SNP distribution among populations further separates a major western cluster into two smaller clusters, the Eastern Atlantic and the Western Mediterranean. It also separates the major eastern cluster into two smaller clusters, the Mid-Mediterranean and Eastern Mediterranean. We suggested here environmental conditions like surface currents, water salinity and temperature as probable factors that have formed the population structure. We demonstrate that C. stellatus is a suitable model organism for studying how geological events and hydrographic conditions shape the fauna in the Mediterranean Sea

Population genetics and reproductive strategies of two Notostraca (Crustacea) species from winter ponds in Israel

Fluorescent-amplified fragment length polymorphism (FAFLP) fingerprinting assay was used to compare the genetic diversity within and between tadpole shrimps (Notostraca) populations of Lepidurus apus (n=7) and Triops cancriformis (n=2) from rain pools in Israel. Each ephemeral water body has revealed a unique fingerprint pattern with an entailed genetic drift between nearby ponds. High similarity of genotypic diversity within each geographic area led to three clusters of water bodies, north, south and center of Israel. FAFLP assays on several newly hatched individuals of T. cancriformis revealed high identity amongst kin, as compared to L. apus where newly hatched from the same maternal source showed high diversity. Results indicate that T. cancriformis populations from Israel are probably parthenogenetic as indicated by clonal structures. The higher genetic variability in the L. apus populations and in laboratory-hatched specimens indicates the existence of sexual reproduction

Speciation, phenotypic plasticity, or ontogeny, the case of the genusGalkinius(Pyrgomatidae, Cirripedia, Crustacea)

Barnacles of the genus Galkinius occupy a large spectrum of host corals, making it one of the least host-specific genera within the Pyrgomatidae. Molecular analyses show that within the genus Galkinius there are highly supported clades, suggesting that the genus Galkinius is a complex of evolutionarily significant units (ESUs). The morphology of the opercular valves has been used as the basis for the separation of species of Galkinius. In this study, morphological variability was found both between specimens within ESUs extracted from different host species and between specimens extracted from the same colony. Identifications based on the opercular valves cannot therefore be assigned to different species despite being genetically distinguishable. It is proposed that in many cases the differences between valve morphology of different species of Galkinius are the outcome of ontogeny. Allometric growth of the valves has resulted in differences in the proportions of the parts of the valve

Flatfoot in Africa, the cirripede Chthamalus in the west Indian Ocean

Barnacles of the genus Chthamalus are commonly encountered rocky intertidal shores. The phylogeography of the different species in the Western Indian Ocean is unclear. Using morphological characteristics as well as the molecular markers mitochondrial cytochrome oxygenase subunit I (COI) and the nuclear sodium-potassium ATPase (NaKA), we identified four clades representing four species in the Western Indian Ocean and its adjacent seas. Among these species, a newly identified species, Chthamalus barilani, which was found in Madagascar, Zanzibar and Tanzania. Chthamalus from the coasts of Tanzania and Zanzibar is identified morphologically as C. malayensis, and clusters with C. malayensis from the Western Pacific and the Indo Malayan regions. C. malayensis is regarded as a group of four genetically differentiated clades representing four cryptic species. The newly identified African clade is genetically different from these clades and the pairwise distances between them justify the conclusion that it is an additional cryptic species of C. malayensis. This type of genetic analyses offers an advantage over morphological characterization and allowed us to reveal that another species, C. barnesi, which is known from the Red Sea, is also distributed in the Arabian Sea and the Persian Gulf. We could also confirm the presence of the South African species C. dentatus in the Mozambique channel. This represents the Northeastern limit of C. dentatus, which is usually distributed along the coast of southern Africa up to the Islands of Cape Verde in West Africa. Altogether, based on a combination of morphology and genetics, we distinct between four clusters of Chthamalus, and designate their distribution in the West Indian Ocean. These distinctions do not agree with the traditional four groups reported previously based merely on morphological data. Furthermore, these findings underline the importance of a combining morphological and genetics tools for constructing barnacle taxonomy

Maternal cardiovascular hemodynamics in normotensive versus preeclamptic pregnancies: a prospective longitudinal study using a noninvasive cardiac system (NICaS™)

Abstract Background Preeclampsia is among the most common medical complications of pregnancy. The clinical utility of invasive hemodynamic monitoring in preeclampsia (e.g., Swan-Ganz catheter) is controversial. Thoracic impedance cardiography (TIC) and Doppler echocardiography are noninvasive techniques but they both have important limitations. NICaS™ (NI Medical, PetachTikva, Israel) is a noninvasive cardiac system for determining cardiac output (CO) that utilizes regional impedance cardiography (RIC) by noninvasively measuring the impedance signal in the periphery. It outperformed any other impedance cardiographic technology and was twice as accurate as TIC. Methods We used the NICaS™ system to compare the hemodynamic parameters of women with severe preeclampsia (PET group, n = 17) to a cohort of healthy normotensive pregnant women with a singleton pregnancy at term (control group, n = 62) (1/2015–6/2015). Heart rate (HR), stroke volume (SV), CO, total peripheral resistance (TPR) and mean arterial pressure (MAP) were measured 15–30 min before CS initiation, immediately after administering spinal anesthesia, immediately after delivery of the fetus and placenta, at the abdominal fascia closure and within 24–36 and 48–72 h postpartum. Results The COs before and during the CS were significantly higher in the control group compared to the PET group (P < .05), but reached equivalent values within 24–36 h postpartum. CO peaked at delivery of the newborn and the placenta and started to decline afterwards in both groups. The MAP and TPR values were significantly higher in the PET group at all points of assessment except at 48–72 h postpartum when it was still significantly higher for MAP while the TPR only exhibited a higher trend but not statistically significant. The NICaS™ device noninvasively demonstrated low CO and high TPR profiles in the PET group compared to controls. Conclusions The immediate postpartum period is accompanied by the most dramatic hemodynamic changes and fluid shifts, during which the parturient should be closely monitored. The NICaS™ device may help the clinician to customize the most optimal management for individual parturients. Our findings require validation by further studies on larger samples