On a parthenogenetic population of Artemia (Crustacea, Branchiopoda) from Algeria (El-Bahira, Sétif)

The brine shrimp Artemia is a small crustacean of hypersaline lakes which is commonely used in larviculture. There are parthenogenetic forms and bisexual species. The formers are from the Old World, and are the most widespread. They are known to prefer high temperatures and relatively stable environments, they are more fertile than sexual species and usually reproduce by ovoviviparity. The parthenogenetic population of Artemia from El-Bahira Lake (10 ha area), situated in the High Plateaus of Northeastern Algeria (1034 m alt), has been characterized and surveyed during two hydroperiods of 2009 and 2013. It has been found to develop only in cold seasons (winter and spring), even if the lake doesn’t dry in summer, and salinities between 46 and 127 ppt. It reproduces by oviparity and produces few cysts (5.69 ± 3.6 and 98.00 ±  28.32 offsprings/brood). Indeed, it behaves more like bisexual Mediterranean populations of A. salina than other parthenogenetic populations. Individual density was much lower during the hydroperiod of 2013, whereas fecundity was higher than in the previous hydroperiod (2009). Cyst reserve was estimated at 133.13 kg of dry weight which corresponds to a rate of 13.31 kg.ha-

On a parthenogenetic population of Artemia (Crustacea, Branchiopoda) from Algeria (El-Bahira, Sétif)

The brine shrimp Artemia is a small crustacean of hypersaline lakes which is commonely used in larviculture. There are parthenogenetic forms and bisexual species. The formers are from the Old World, and are the most widespread. They are known to prefer high temperatures and relatively stable environments, they are more fertile than sexual species and usually reproduce by ovoviviparity. The parthenogenetic population of Artemia from El-Bahira Lake (10 ha area), situated in the High Plateaus of Northeastern Algeria (1034 m alt), has been characterized and surveyed during two hydroperiods of 2009 and 2013. It has been found to develop only in cold seasons (winter and spring), even if the lake doesn’t dry in summer, and salinities between 46 and 127 ppt. It reproduces by oviparity and produces few cysts (5.69 ± 3.6 and 98.00 ±  28.32 offsprings/brood). Indeed, it behaves more like bisexual Mediterranean populations of A. salina than other parthenogenetic populations. Individual density was much lower during the hydroperiod of 2013, whereas fecundity was higher than in the previous hydroperiod (2009). Cyst reserve was estimated at 133.13 kg of dry weight which corresponds to a rate of 13.31 kg.ha-

Ecological and biological characterisrics of Artemia salina (Crustacea, Anostraca) in the sebkha Ez-Zemoul, northeastern Algeria

This study concerned some biological and ecological aspects of Artemia salina (Branchiopoda, Anostraca) from the sebkha Ez-Zemoul, situated in northeastern Algeria (35° 53’ N - 06° 30’ E). The survey of the demographic structure and density of Artemia population between January 2003 and February 2005 shows that this brine shrimp appeared in November after the cyst hatching, reached a maximum density in March (56 ind/L in 2003 and 38 ind/L in 2004) and disappeared completely in July. The sex ratio was always in favour of males. Its values were very high (1.77 - 31.80). Males were smaller than females. Their respective lengths varied, according to the sampling period, between 7.1 mm and 8.8 mm and between 8.7 mm and 10.4 mm. The length of females at first sexual maturity varied between 7 mm (November) and 9 mm (April). Oviparity was the main mode of reproduction (90 - 100 %). Females were relatively fertile with an average brood size comprised between 19.50 (May 2003) and 104.7 (March 2003) offsprings/femaleCette étude est consacrée à quelques aspects de l'écologie et de la biologie d'Artemia salina (Branchiopode, Anostracé) de la sebkha Ez-Zemoul, située dans le nord-est de l'Algérie (35°53' N - 06°30' E). Le suivi de sa structure démographique et de sa densité, entre janvier 2003 et février 2005, montre que ce crustacé apparaît en novembre, suite à l'éclosion des cystes, atteint une densité maximale en mars (56 ind/L en 2003 et 38 ind/L en 2004) et disparaît complètement à partir de juillet. La sex-ratio est toujours en faveur des mâles et ses valeurs sont très élevées (1,77 - 31,80). Ces derniers sont plus petits que les femelles. Les tailles moyennes des deux sexes varient, selon la période d'échantillonnage, entre 7,1 mm et 8,8 mm et entre 8,7 mm et 10,4 mm respectivement. La taille à la première maturité sexuelle des femelles varie entre 7 mm (novembre) et 9 mm (avril). L'oviparité est le principal mode de reproduction (90 - 100 %). La fécondité varie entre 19,5 (mai 2003) et 104,7 zygotes/portée (mars 2003)

Physico-chemical characterization of three permanent saline lakes from Oued Righ valley (Northern Sahara, North-East Algeria)

Les lacs Ayata, Mégarine et Témacine sont parmi les rares plans d’eaux salés et permanents du Sahara algérien. Il s’agit de dépressions de quelques hectares inondées par des puits artésiens creusés aux siècles derniers pour l’irrigation des palmeraies. Afin de les caractériser du point de vue physico-chimique, une analyse mensuelle de treize facteurs physico-chimiques (température, conductivité électrique, salinité, pH, oxygène dissous, NO2-, NO3-, HCO3--, Cl-, SO4-- , Na+, K+ et Ca++) a été effectuée entre août 2009 et mars 2010. Mégarine est le plus salé avec un maximum de 35,00 ± 0,28 g.L-1. Ayata et Témacine sont considérés comme saumâtres-salés. La température de l’eau est similaire dans les trois lacs et varie entre 15,70 et 34,25 °C. Le pH est alcalin et varie entre 7,23 et 8,05. L’oxygène dissous est faible avec un maximum de 4,52 mg.L-1, soit 50,51 % de saturation à Témacine. Les trois lacs sont fortement minéralisés avec une dominance des chlorures, des sulfates et du calcium. L’analyse de la matrice de corrélations linéaires de Pearson montre que la température est le principal facteur influençant les variations de la salinité, de la conductivité et de l’oxygène dissous. La salinité, plus élevée à Mégarine, est due principalement à deux sels KCl et NaCl, avec une dominance du premier. Les Cl-, SO4--, Na+ et K+ proviennent des évaporites des nappes souterraines et des sols adjacents, alors que les HCO3- proviennent de la calcite et/ou de la dolomite des nappes et des sols traversés, ainsi que d’une source biologique. Le Ca++ provient de la calcite et/ou de la dolomite. Globalement, le climat, les apports en eaux des nappes souterraines, les sols adjacents et les systèmes d’évacuation artificiels placés dans les lacs Ayata et Témacine sont les principaux facteurs contrôlant le fonctionnement physico-chimique de ces écosystèmes.Characterized by its richness in wetlands, Oued Righ valley is located in the northeast of Algerian Sahara, where most of the water resources originate from the groundwater of two aquifers: the intermediate continental (CI) and the terminal complex (CT). These wetlands are of major interest because they are considered important for food for waterbirds, and in the future, they might be potential sites for Saharan aquaculture. Little is known about the hydrology of these areas, the few existing physico-chemical investigations only concern drillings and Oued Righ channel. Here, for the first time we provide physico-chemical data of three permanent saline lakes in this region: Ayata, Mégarine and Témacine Lakes. In order to characterize them, a monthly analysis of thirteen factors (temperature, electrical conductivity, salinity, pH, dissolved oxygen, NO2-, NO3-, HCO3--, Cl-, SO4--, Na+, K+ and Ca++ ) was conducted between August 2009 and March 2010. The results show that Mégarine was the saltier with 35.00 ± 0.28 g.L-1. Ayata and Témacine are considered brackish and salty (11.56 ± 0.93 g.L-1 and 16.45 ± 0.35 g.L-1, respectively). Water temperature was similar in the three lakes and varied between 15.70 °C in winter and 34.25 °C in summer. Their pH was alkaline and between 7.23 and 8.05. Dissolved oxygen was low with a maximum of 4.52 mg.L-1 which corresponds to 50.51 % of saturation in Témacine. These lakes are highly mineralized; sulphate, chlorides and calcium were dominant. The analysis of Pearson’s linear correlation matrix shows that temperature was the main factor influencing the changes in salinity, conductivity and dissolved oxygen. The higher salinity in Mégarine was due to the two salts KCl and NaCl, with a dominance of the first. Cl-, SO4--, Na+ and K+ originated from groundwater and adjacent soil evaporates, whereas HCO3-- came from groundwater and adjacent soil calcite and /or dolomite, and from a biological source. The Ca ++ was from calcite and /or dolomite. Globally, climate, groundwater, the adjacent soils and artificial drainage systems in Ayata and Témacine were the main factors controlling the physico-chemical functioning of these ecosystems

Observations on Phallocryptus Spinosa (Branchiopoda, Anostraca) Populations from the high Plateaus of Northeastern Algeria

Phallocryptus spinosa (Thamnocephalidae) is a small primitive crustacean which lives in temporary saline pools of the Palaearctic region called Chott, Sebkha, Garâa or Daya in North Africa. Data on its biology and life history are very scarce despite its ecological importance in wetlands. Four populations living in the Northeastern High Plateaus of Algeria, Garâas Guellif, El-Tarf, Ank Djemel and Sebkha Ez-Zemoul, have been studied in point of view of their morphmetry (13 parameters) and their reproduction. The population of Sebkha Ez-Zemoul, living in higher salinities and in sympatry with Artemia salina was different from the 3 other populations that are close together. Its adults are the largest (21.77 ± 2.34 mm and 23.65 ± 2.36 mm for males and females respectively) and produce more cysts 771.47±8.45 cysts/brood of 293.11±10.41 µm diameter. Associated carcinological fauna and some behavioral traits are also approached

Observations on Phallocryptus Spinosa (Branchiopoda, Anostraca) Populations From the High Plateaus of Northeastern Algeria

Phallocryptus spinosa (Thamnocephalidae) is a small primitive crustacean which lives in temporary saline pools of the Palaearctic region called Chott, Sebkha, Garâa or Daya in North Africa. Data on its biology and life history are very scarce despite its ecological importance in wetlands. Four populations living in the Northeastern High Plateaus of Algeria, Garâas Guellif, El-Tarf, Ank Djemel and Sebkha Ez-Zemoul, have been studied in point of view of their morphmetry (13 parameters) and their reproduction. The population of Sebkha Ez-Zemoul, living in higher salinities and in sympatry with Artemia salina was different from the 3 other populations that are close together. Its adults are the largest (21.77 ± 2.34 mm and 23.65 ± 2.36 mm for males and females respectively) and produce more cysts 771.47±8.45 cysts/brood of 293.11±10.41 µm diameter. Associated carcinological fauna and some behavioral traits are also approached

On a parthenogenetic population of Artemia (Crustacea, Branchiopoda) from Algeria (El-Bahira, Sétif)

The brine shrimp Artemia is a small crustacean of hypersaline lakes which is commonly used in larviculture. The parthenogenetic population of Artemia from El-Bahira Lake (10 ha area), situated in the High Plateaus of Northeastern Algeria (1034 m alt), has been characterized and surveyed during two hydroperiods of 2009 and 2013. Contrary to other known parthenogenetic populations, which develop in hot seasons and reproduce by ovoviviparity, Artemia from El-Bahira was found to develop only in cold seasons (winter and spring), even if the lake doesn’t dry in summer. It reproduces by oviparity and produces few cysts (5.69 ± 3.6 and 98.00 ± 28.32 offsprings/brood). Individual density was much lower during the hydroperiod of 2013, whereas fecundity was higher than in the previous hydroperiod (2009). Cyst reserve was estimated at 133.13 kg of dry weight which corresponds to a rate of 13.31 kg.ha-1

Taxonomic status of Macaronesian <I>Eucyclops agiloides azorensis</I> (Arthropoda: Crustacea: Copepoda) revisited – morphologysuggests a Palearctic origin

Macaronesia, with the exception of the Azores, is one of the few Palearctic provinces where basic taxonomic information on the freshwater copepods is still lacking. We redescribed Eucyclops azorensis, a cyclopid crustacean so far known only in the Azores, and report the occurrence of this species in Algeria and Madeira Island. Eucyclops azorensis was formerly considered to be a subspecies of E. agiloides (East Africa); therefore, the latter species is redescribed here as well based on type and non-type material. Morphological comparisons between E. azorensis, E. agiloides and other taxa (E. serrulatus and E. roseus), assumed to be closely related to our target species, support a closer relationship between E. azorensis and E. serrulatus (Palearctic) than between E. azorensis and E. agiloides (Afrotropical). The slight differences between E. azorensis and E. serrulatus in the surface ornamentation of the antennal coxobasis and intercoxal sclerites of legs 1 and 4 suggest a relatively young separation of these lineages. Eucyclops agiloides is morphologically close to E. roseus (temperate and subtropical Asia, southeastern Europe, East Africa). The numerous and clear-cut differences indicate a species rather than subspecies-level diff erentiation between E. agiloides and E. roseus, unlike what was formerly proposed in the taxonomic literature.</p

Chirocephalidae Daday 1910

Family Chirocephalidae Daday, 1910 Subfamily Chirocephalinae Daday, 1910Published as part of Boumendjel, Lylia, Rabet, Nicolas & Amarouayache, Mounia, 2018, Chirocephalus sanhadjaensis sp. nov., a new chirocephalid species (Branchiopoda: Anostraca) from Numidia (Algeria), pp. 381-391 in Zootaxa 4526 (3) on page 382, DOI: 10.11646/zootaxa.4526.3.7, http://zenodo.org/record/261174

Chirocephalus sanhadjaensis Boumendjel & Rabet & Amarouayache 2018, sp. nov.

&lt;i&gt;Chirocephalus sanhadjaensis&lt;/i&gt; sp. nov. &lt;p&gt;(Figs. 3, 4, 5, 6)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; The specific epithet &ldquo; &lt;i&gt;sanhadjaensis&lt;/i&gt; &rdquo; refers to the Guerbes-Sanhadja wetlands complex of international importance (Ramsar 2001) where the Ain-Magroun and Belkroun pools are situated.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type locality&lt;/b&gt;. Ain-Magroun, a temporary freshwater pond (coordinates: 36&deg;50'20.99&quot; N, 7&deg;17'01.17&quot; E, altitude 19 m a.s.l) (Fig. 1). The pond is located in a meadow in the municipality of Ben Azzouz (Skikda Province, Northeastern Algeria) and is part of the Guerbes-Sanhadja wetlands complex. The pool has an oval shape and an area of about 1000 m 2, with a maximum depth of 0.5 m (Fig. 2A), and with some humid depressions in its periphery. It generally inundates in January or February and dries out in April. During our sampling in January 2015 the pH was of 7.13, water conductivity 154 &micro;S/cm and temperature 9.4&deg;C.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Chirocephalus sanhadjaensis&lt;/i&gt; appears to be restricted to the type locality and two small temporary pools in Belkroun (Ben Azzouz, Province of Skikda) located about 10 km east of Ain-Magroun pond (36&deg;51'59.13&quot;N, 7&deg;23'37.35&quot;E, altitude 6 m a.s.l.). These pools are artificial water holes for livestock watering with an area of about 16 m 2 and a maximum depth of about 2.5 m. During our sampling in December 2017, pH was of 7.15, conductivity of 262 &micro;S/cm and water temperature of 10.9&deg;C (Fig. 2B). The distribution of this species seems to be limited to the Guerbes-Sanhadja wetland complex, where agricultural activities are important.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Type material. Holotype.&lt;/b&gt; Mature male of 17.8 mm total length; Algeria: Skikda Province: Ain-Magroun temporary pond; 11 January 2015; S. Ghaouaci leg; stored in 96% ethanol after formalin fixation (MNHN-IU- 2017-2317).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Allotype.&lt;/b&gt; Mature female of 16.8 mm total length: same data as the holotype (MNHN-IU- 2017-2318). &lt;b&gt;Paratypes:&lt;/b&gt; Two males of 16 and 17.6 mm total length (MNHN-IU- 2017-2319); same data as holotype. Two females of 12 and 12.8 mm total length (MNHN-IU- 2017-2320); Algeria: Skikda Province: Belkroun; 20 December 2017; M. Amarouayache leg; stored in ethanol 96% after formalin fixation. &lt;b&gt;Description. Male.&lt;/b&gt; Living specimens have a transparent to greenish colour with a vermillion furcae.&lt;/p&gt; &lt;p&gt; &lt;i&gt;First antennae&lt;/i&gt; filiform, with apical setae, with a length 0.7x of the second antenna proximal antennomere.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Second antennae&lt;/i&gt; (Fig. 3C) proximal antennomere curved medially, bearing an apophysis total length ~1.1x distal antennomere. Apophysis subconic, digitiform; apex with denticles; total length ~0.25x of the proximal antennomere. Second antennae distal antennomere with a proximal, medially directed, ~30&deg; bend, apically truncated, and bearing a proximedial projection and a spiniform projection, just distal to the proximedial projection (Fig. 3D). Proximedial projection lobiform, distal surface bearing scattered denticles or apically truncated spinulae; total length ~0.2x article length. Antennal appendage (Fig. 3A) total length 0.6x second antenna. Basal lamella (ventral lamella) triangular, apex elongate, with a small dorsal carina. Basal lamella margins bearing small, evenly distributed papillae, with the medial margin provided with three rows of papillae. Lateral margin papillae each with an apical denticle (Fig. 3B). Antennal appendage dorsal lamella length 1.7x basal lamella, serrate in the distal half with medial and lateral margins bearing subtriangular papillae (larger medially) diminishing in size distally; apex acute. Medial papillae with posterior margin edged in short setae.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Labrum&lt;/i&gt;. Distal lobe rounded, 0.5 x of length exceeding the distal margin of the labrum.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Mandibles&lt;/i&gt; asymmetrical, right mandible molar surface with two posterio-apical acute spines, equal in length; molar surface of left mandible bearing a row of eight robust teeth on the lateral outer margin.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Maxilla I&lt;/i&gt;. Typical for the genus (Cottarelli &lt;i&gt;et al.&lt;/i&gt; 2010; 2017). Setae aciculate and straight; there is also a posterior ventral acute spine.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Maxilla II&lt;/i&gt; rounded lobe bearing two robust plumose apical setae, approximately equal.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Phyllopodia&lt;/i&gt; with gross structure typical for genus. Thoracopod I (Fig. 4A), with the first three endites (I to III) arcuate, rounded. Endite I and II fused, four to five times as broad as long. Endite III two times as broad as long, with two plumose acute spines 0.5 x broad of the endite. Endites I to III margined with long plumose setae, four to five times the endite length, decreasing in length medially. Endites IV to VI rounded as broad as long (Fig. 4C). Endite IV with six plumose acute spines, each two times the endite length. Endite V and VI with four plumose acute spines, each two times the endite length.&lt;/p&gt; &lt;p&gt;Thoracopod VI (Fig. 4E), with endite I and II fused, arcuate, rounded, five times as broad as long. Endite III, arcuate, rounded, two times as broad as long. Endites I to III margined with long plumose setae, five to six times the endite length, decreasing in length medially. Endite IV and V lamellar, with two plumose acute spines each twice the endite length. Endite VI lamellar, with three plumose acute spines, each two times the endite length.&lt;/p&gt; &lt;p&gt;Thoracopods I to X with endopod (Fig. 4B) broad, forming right angle to limb, bearing short, plumose acute marginal spines. Exopod oval, margined with a few small plumose spines and a long plumose setae apically. Epipodite subcylindrical, length 4x width. Praepipodite completely divided in two, broadly rounded distally, with margin serrate and inerm.&lt;/p&gt; &lt;p&gt;Thoracopod XI (Fig. 4D), with endite I and II fused, arcuate, rounded, six times as broad as long. Endite III, arcuate, rounded, two times as broad as long. Endites I to III margined with plumose setae, two to three times the endite length, decreasing in length medially. Endites IV to VI rounded as broad as long. Endite IV and V with 3 plumose acute spines each two times the endite length. Endite VI with four plumose acute spines, each two times the endite length.&lt;/p&gt; &lt;p&gt;Thoracopod XI without praepipodite (branchial lamina) and with a conical epipodite three times longer than its width, with acute apex and without spine or setae.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Gonopod&lt;/i&gt; (Fig. 5B) typical for the genus, with a lateral conical lobe. Gonopod rigid basal portion subtriangular, medially margined in dense setae. Eversible portion of the gonopods (Fig. 5A) represented by conical and curved apex bearing one tiny tubercle.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Abdominal-somites&lt;/i&gt; smooth, without projections.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Cercopods&lt;/i&gt; length does not exceed the length of last three abdominal segments; cercopods bordered with long plumose setae.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Female.&lt;/b&gt; transparent to greenish colour with vermillion furcae.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Second antennae&lt;/i&gt; slightly shorter by 20 % than the first pair of antennae, flattened, subconical apex acute.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Thoracopods I-XI&lt;/i&gt; (Fig. 4G, H, I) as in the male.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Genital somites&lt;/i&gt;. First genital somite reaches half the length of the second one (Fig. 5C).&lt;/p&gt; &lt;p&gt;Brood pouch conical, extending to the third or fourth abdominal somite with gonopore typical for genus.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Abdominal somites and cercopods&lt;/i&gt; (Fig. 5D) similar to those of males.&lt;/p&gt; &lt;p&gt;Eggs. (Fig. 6) shell with high and thin palisaded structure delimiting more or less regular polygons. Diameter of eggs: (448.24 &plusmn; 30.93 &micro;m, n =90).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Size.&lt;/b&gt; Male average length 17.4 &plusmn; 1.66 mm (14-21.3 mm, N = 19). Female average length of 17.9 &plusmn; 2 mm (14- 19.7 mm, N = 6),&lt;/p&gt; &lt;p&gt; &lt;b&gt;Differential diagnosis.&lt;/b&gt; &lt;i&gt;Chirocephalus sanhadjaensis.&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. is most similar to &lt;i&gt;C. marchesonii&lt;/i&gt; and &lt;i&gt;C. tauricus&lt;/i&gt;. These species are separated from all other &lt;i&gt;Chirocephalus&lt;/i&gt; by the shape of the male antennal appendage and by large eggs. &lt;i&gt;Chirocephalus sanhadjaensis.&lt;/i&gt; &lt;b&gt;sp. nov.&lt;/b&gt; is separated from &lt;i&gt;C. marchesonni&lt;/i&gt; and &lt;i&gt;C. tauricus&lt;/i&gt; by the second antenna distal antennomere having a distinct basomedial projection and proximal spiniform projections present only in this species.&lt;/p&gt; &lt;p&gt; In &lt;i&gt;C&lt;/i&gt;. &lt;i&gt;sanhadjaensis&lt;/i&gt; &lt;i&gt;.&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;., the male second antennal distal antennomere is slightly curved in its proximal portion, and almost straight for the apical length as in &lt;i&gt;C. marchesonii&lt;/i&gt; Ruffo &amp; Vesentini, 1957, &lt;i&gt;C. neumanni&lt;/i&gt; Hartland-Rowe, 1967 and &lt;i&gt;C. algidus&lt;/i&gt; Cottarelli &lt;i&gt;et al.&lt;/i&gt; 2010 but not in &lt;i&gt;C. diaphanus&lt;/i&gt; Pr&eacute;vost, 1803 or &lt;i&gt;C. salinus&lt;/i&gt; Daday, 1910, where the distal portion is more curved, or in &lt;i&gt;C. tauricus&lt;/i&gt; Pesta, 1921 where the distal antennomere widens apically and is somewhat spatulate.&lt;/p&gt; &lt;p&gt; In &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. the basal process of the distal antennomere of the antennae is well developed, rather straight with denticles and a slightly curved apex, while this basal process of the distal antennomere is short and slightly pointed, devoid of teeth in &lt;i&gt;C. marchesonii&lt;/i&gt;. &lt;i&gt;Chirocephalus algidus&lt;/i&gt; has a quite elongated and narrow, straight and dentate basal process, and in &lt;i&gt;C. tauricus&lt;/i&gt; the basal process is small and pointed, with a curved apex directed backwards (Cottarelli &lt;i&gt;et al.&lt;/i&gt; 2010).&lt;/p&gt; &lt;p&gt; The long basolateral digitiform expansions of the dorsal lamella are present in many species of the genus &lt;i&gt;Chirocephalus, e.g. C. diaphanus, C. salinus&lt;/i&gt;, also in representatives of other species-groups of the genus &lt;i&gt;Chirocephalus&lt;/i&gt;, e.g. &lt;i&gt;C&lt;/i&gt;. &lt;i&gt;sarpedonis&lt;/i&gt; Cottarelli &lt;i&gt;et al.&lt;/i&gt; 2017, &lt;i&gt;C. croaticus&lt;/i&gt; Steuer, 1899, &lt;i&gt;C. kerkyrensis&lt;/i&gt; Pesta, 1936; but they are absent in &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. as in &lt;i&gt;C. appendicularis&lt;/i&gt; V&agrave;vra, 1905, &lt;i&gt;C. marchesonii, C. tauricus&lt;/i&gt;, &lt;i&gt;C. skorikowi&lt;/i&gt; Daday, 1913, &lt;i&gt;C. weisigi&lt;/i&gt; Smirnov, 1933, &lt;i&gt;C. neumanni,&lt;/i&gt; &lt;i&gt;C. ponticus&lt;/i&gt; Beladjal &amp; Mertens, 1997 and &lt;i&gt;C. algidus&lt;/i&gt; Cottarelli &lt;i&gt;et al.&lt;/i&gt; 2010. The dorsal lamella of &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. and &lt;i&gt;C. marchesonii&lt;/i&gt; is 1.5x long than the basal lamella. In &lt;i&gt;C. tauricus&lt;/i&gt; and &lt;i&gt;C. weisigi&lt;/i&gt; the dorsal lamella is short, half the length of the basal lamella, while in &lt;i&gt;C. algidus&lt;/i&gt; the dorsal lamella, is somewhat longer than the basal lamella (Cottarelli &lt;i&gt;et al&lt;/i&gt;. 2010). Basal lamella of &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt; exhibits a small carina, present also in &lt;i&gt;C. marchesonii, C. algidus&lt;/i&gt; and several other taxa of the &ldquo; &lt;i&gt;diaphanus&lt;/i&gt; &rdquo; group, where the size of carina differs between species. However, it is absent in &lt;i&gt;C. tauricus&lt;/i&gt; and &lt;i&gt;C. salinus&lt;/i&gt;. The outline of the basal lamella of &lt;i&gt;C. sanhadjaensis&lt;/i&gt; resembles that of &lt;i&gt;C. tauricus&lt;/i&gt; and &lt;i&gt;C. marchesonii&lt;/i&gt;, with margins bearing small, evenly distributed papillae, with the medial margin bearing several papillae.&lt;/p&gt; &lt;p&gt; The brood pouch of &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. is conical, reaching the 3 th or 4 th abdominal segment and is similar in shape to that of &lt;i&gt;C. diaphanus&lt;/i&gt;, &lt;i&gt;C. salinus&lt;/i&gt; and several other species of the &ldquo; &lt;i&gt;diaphanus&lt;/i&gt; &rdquo; group. The brood pouch of &lt;i&gt;C. algidus&lt;/i&gt; is thick and very short (does not reach the length of the two subsequent somites), while in &lt;i&gt;C. tauricus&lt;/i&gt; and &lt;i&gt;C. marchesonii&lt;/i&gt; the brood pouch is somewhat longer than &lt;i&gt;C. algidus&lt;/i&gt; although different in shape, swollen in &lt;i&gt;C. tauricus&lt;/i&gt; (Cottarelli &lt;i&gt;et al&lt;/i&gt;. 2010).&lt;/p&gt; &lt;p&gt; In &lt;i&gt;C. sanhadjaensis&lt;/i&gt; &lt;b&gt;sp. nov&lt;/b&gt;. the egg ornamentations are similar to those of &lt;i&gt;C. diaphanus&lt;/i&gt; and many other species in the genus. However, the egg diameter is particularly large (448.24 &micro;m). Indeed, &lt;i&gt;C. marchesonii&lt;/i&gt; is the second species in the group that produces eggs with a diameters exceeding 430 &micro;m, but its eggs are easily distinguishable by their smooth and fibrous surface (Mura &lt;i&gt;et al.&lt;/i&gt; 1978; Mura, 2001).&lt;/p&gt;Published as part of &lt;i&gt;Boumendjel, Lylia, Rabet, Nicolas &amp; Amarouayache, Mounia, 2018, Chirocephalus sanhadjaensis sp. nov., a new chirocephalid species (Branchiopoda: Anostraca) from Numidia (Algeria), pp. 381-391 in Zootaxa 4526 (3)&lt;/i&gt; on pages 382-386, DOI: 10.11646/zootaxa.4526.3.7, &lt;a href="http://zenodo.org/record/2611741"&gt;http://zenodo.org/record/2611741&lt;/a&gt