New record of the sponge-dwelling shrimp Typton distinctus Chace, 1972 (Decapoda: Caridea: Palaemonidae) in São Paulo State, Brazil

Among the Caridea Infraorder, the palaemonid shrimp from the genus Typton Costa, 1844 are commonly found in association with sponges, frequently feeding on the tissues of their hosts ((Ďuriš et al. 2011; Almeida et al. 2014; Pachelle et al. 2015; Soledade et al. 2017). Typton is mostly characterized by morphological features related to their sponge-dwelling lifestyle, as a simple and compressed rostrum, carapace smooth and antennal spines present, antennae extremely reduced and scaphocerite rudimentary. Mandible without palp, incisor process normal, reduced or absent. Second legs unequal, asymmetrical, without molar process on major chela (Bruce, 1972)

The atyid shrimps from Lake Lindu, Central Sulawesi, Indonesia with description of two new species (Crustacea: Decapoda: Caridea)

The atyid shrimp Caridina linduensis Roux, 1904, has not been reported since its description more than a century ago. We here redescribe and figure this poorly known species based on new material from its type locality, Lake Lindu, Central Sulawesi, Indonesia. Two new species, C. dali sp. nov. and C. kaili sp. nov. are also found in this lake and they are described and illustrated. Compared to C. linduensis, C. dali sp. nov. is distinguished by its relatively shorter rostrum which only overreaches the end of basal segment of antennular peduncle and the fewer teeth on the incisor process of the mandible. Caridina kaili sp. nov. can be separated from C. linduensis by its extremely short rostrum, which reaches almost or just reaches the end of the basal segment of the antennular peduncle, proportionately stouter second pereiopod and larger egg size. The two new species also prefer different habitats; C. linduensis is a true lake inhabitant, C. dali sp. nov. can be found both in the lake itself and associated streams while C. kaili sp. nov. is an obligate stream species.

On the “Hippolyte commensalis Kemp, 1925” species complex (Decapoda, Caridea, Hippolytidae), with the designation of a new genus and description of two new species from the Indo-West Pacific

Only one species of hippolytid shrimp, namely Hippolyte commensalis Kemp, 1925, was previously known to be associated with alcyonacean soft corals (Octocorallia, Alcyonacea) in the Indo-West Pacific. Recent collections revealed that at least three distinct hippolytid species are associated with alcyonacean soft corals. Moreover, these alcyonacean-associated hippolytids differ considerably from all other species of the genus Hippolyte Leach, 1814 in having a smooth rostrum bearing a single subapical ventral tooth, reduced styliform incisor process of the mandible, the basal antennular segment without ventromedial tooth, and the ambulatory pereiopods lacking or with only relatively small distoventral spines. A new genus, Alcyonohippolyte gen. nov., is thus established for Hippolyte commensalis Kemp, 1925 and two new species. Alcyonohippolyte dossena sp. nov. (the type species of the new genus) mainly differs from the congeners in having a humpbacked carapace. Alcyonohippolyte maculata sp. nov. closely resembles A. commensalis but clearly differs in having a furry carapace and distinct coloration, as well as in association with different alcyonacean host. An identification key is provided as well as information on the live coloration and host for all species of Alcyonohippolyte gen. nov.

Periclimenaeus pectinidactylus n. sp. (Crustacea: Decapoda: Pontoniinae) from the Belizean Barrier Reef, Caribbean Sea

A new species of sponge-associated pontoniine shrimp from the Belizean Barrier Reef in the Caribbean Sea is described and illustrated, and its systematic position is discussed. The single specimen available is incomplete, lacking the major second pereiopod. A comb-like arrangement of the cutting edges on the first pereiopod fingers is unique within the genus. A very short carpocerite and a strongly reduced incisor process on the mandible are among other features which are rare in other Periclimenaeus species.

A review of taxonomic concepts in the Nannoniscidae (Isopoda, Asellota), with a key to the genera and a description of Nannoniscus oblongus Sars

Owing to recent taxonomic changes to the Nannoniscidae Hansen, the concepts of the taxa within the family require clarification. Specimens of Nannoniscus oblongus Sars, putatively those examined by G.O. Sars, and specimens from Hjeltefjord, Norway were illustrated to clarify the concept of the type genus of the Nannoniscidae. Specimens used by Siebenaller and Hessler (1981) and several other recently-described taxa were evaluated. Standard views are argued to provide more consistent illustrations of morphology. The somite articulations of the posterior body were found to be variable and often inaccurately illustrated feature in nannoniscid taxonomy; this character complex is therefore unreliable for taxonomic concepts in the family. In replacement, new characters that distinguish this family from the Desmosomatidae Sars are described. These include the proximal segmentation of the antennal flagellum, a subdistal dorsal tooth on the left mandible incisor process and ventral pereonal insertions of the coxae. The composition and classification of the family is adjusted using this new information. Subfamilies recently proposed for the Nannoniscidae by George (2001) based on somite articulations are rejected. Diagnoses of several genera, including Saetoniscus Brandt, were reconsidered using this new information. This latter genus is found to be indistinguishable from Nannoniscus Sars and is placed in junior synonymy. A new diagnosis and a new key to the genera of the Nannoniscidae use the new character information, omitting somite articulations as a primary descriptor. New diagnoses for Nannoniscus Sars and Nannonisconus Schultz, and revised compositions for these genera are proposed. Nannoniscus intermedius Siebenaller & Hessler is transferred to Nannonisconus. Rapaniscus Siebenaller & Hessler is diagnosed and pereopods I–II of its type species, R. dewdneyi are illustrated.

Relevant role of the labrum associated with the mandibles in the Lophogaster typicus digestive function

This study was aimed at understanding the diet and the digestive function of the deep-living Lophogastrida species Lophogaster typicus (Mysidacea: Lophogastrida). Scanning electron microscopy (SEM) investigations have revealed that the mandibles exhibit typical features of a carnivorous diet, i.e. large and sharp incisor process and small molar one with only few scales. The analysis of gut contents confirms morphological data as crustacean remains have been recognized. However, the presence of a large quantity of unidentifiable soft particulate matter also indicates a saprophagous tendency. The external asymmetrical edge of the labrum consists of a small grinding area. The entire external face of the labrum exhibits numerous pores, which are related with glandular units. These units are organized into acini of two to four large cells. Two types of acini have been observed, i.e. with dark or clear cells. According to ultrastructural and cytochemical data, labral secretions are believed to be mucopolysaccharidic (for clear acini) and enzymatic components (for dark acini), and are therefore involved both in coating and in digesting the food. Moreover, presence of neuronal endings and endocrine cells, both associated with glandular units, and comparison between glandular units in starved and fed animals suggest a controlled release of the secretions. Therefore, the labrum plays a crucial role in the digestive function of the lophogastrid crustacean L. typicus, as it involves both mechanical and chemical breakdown of the food.

The Lower Carboniferous shrimp Tealliocaris from Gullane, East Lothian, Scotland

ABSTRACTTealliocaris is probably one of the best preserved of all Carboniferous crustaceans. It occurs scattered through the 12 cm thick laminated Gullane ‘shrimp-bed’. The cuticle is exceptionally well preserved and the specimens, which are normally complete, are infilled with fluorapatite. The carapace has an elongate rostrum, a defined frontal area, a median ridge and paired gastric and inner and outer lateral ridges. The eyes are borne on a stout peduncle. The first antenna bears a pair of flagella, the second an antennal scale and long flagellum. The mandible is large and heavily sclerotised with molar and incisor process. The maxillae and anterior thoracopods are poorly preserved. The posterior six thoracopods each have a long segmented endopod and annulated setose exopod. More than half the specimens preserve lamellae which may represent branchial epipods, or floor a brood chamber beneath the carapace on either side of the thorax. The pleopods are biramous. The telson and uropods form a tail fan. In the absence of oostegites Tealliocaris cannot be assigned to the order Mysidacea but its affinities lie close to these Eumalacostraca. Tealliocaris walked on the thoracic endopods, but could also swim using the pleopods and thoracic exopods. The mode of feeding is uncertain. Tealliocaris probably inhabited a brackish lake or lagoon, but its distribution elsewhere suggests that it may have been tolerant of a range of salinities.

The morphology, mode of life, and affinities of Canadaspis perfecta (Crustacea: Phyllocarida), Middle Cambrian, Burgess Shale, British Columbia

A detailed description and reconstruction of Canadaspis perfecta demonstrates its status as the earliest well-preserved crustacean. The cephalon consisted of five somites (in addition to the eyes), the thorax eight, and the abdomen seven, excluding the telson. Two pairs of apparently uniramous antennae flanked a median cephalic spine. The mandible bore a massive incisor process posterior of a molar area made up of finer spines, and apparently lacked a palp. The first and second maxillae were essentially similar to the eight pairs of thoracopods, with a multisegmented inner ramus, and foliaceous outer ramus made up of wide filaments attached to a proximal lobe. A bivalved carapace covered the thorax; no rostral plate was present. The abdomen lacked appendages, apart from a pair of spinose ventral projections of the pre-telson somite. There was no caudal furca. The evidence suggests that C. perfecta fed on coarse particles, possibly with the aid of currents set up by the biramous appendages. The erection of a new order Canadaspidida and family Canadaspididae Novozhilov (in Orlov 1960) to include Canadaspis is vindicated, and they are re-defined and the subclass Phyllocarida amended to include them.

VII. The formation and early growth of the bones of the human face

These notes refer to some few points with which we are as yet imperfectly acquainted, such as the growth of the maxilla, and the formation and subsequent obliteration of the intermaxillary bones. As they are simply a narration of facts, it is almost impossible to give a satisfactory abstract of them. After brief consideration of the arrangement of the cartilages for the ethmoid and turbinate bones and for the septum of the nose, an account is given of the appearances observed in a human fœtus four-tenths of an inch long, noticing the relations of the maxillary lobes, of the parts which represent the palate, and showing that the opposite sides unite from before backwards to form the palate, the soft palate remaining ununited in a fœtus one inch and five-tenths long. The superior maxilla is described, before ossification has commenced, in a fœtus nine-tenths of an inch long. Although ossification begins in this bone at many distinct points, the rapidity with which the separate ossifications are fused make it undesirable to name each as a distinct centre. The palatal and alveolar portions are formed somewhat later than the remainder of the bone. In a fœtus two inches and three-tenths long the bone consists of a nasal process, deeply grooved on its inner surface, of an incisor process, which has not hitherto been accurately described, of orbital and of palatal-alveolar portions; the infraorbital fissure is distinctly marked, and a deep notch shows the situation of the canine socket.