Description of a new species of emGlassella/em Campos amp; Wicksten, 1997 from a coastal lagoon, SE Gulf of California (Crustacea, Decapoda, Pinnotheridae).

A new a species of pinnotherid crab in the eastern Pacific coasts is presented. Twenty males and 21 females of small crabs were collected from burrows, presumably from ghost shrimp (Neotrypaea spp.), in sand-mud substrata from the Santa María-La Reforma coastal lagoon, SE Gulf of California. The new species was assigned to the genus Glassella because its morphological characteristics clearly match the amended diagnosis of the genus Glassella by Palacios Theil and Felder (2020) and Felder Palacios Theil (2020), including the presence of a gonopodal plate (GP) inserted in the internal part of the male pleon, similar to that described for most of the species currently grouped into the genus Glassella. The new species is similar to G. miamiensis (McDermott, 2014) from western Atlantic, but it can be distinguished from this and the rest of the species of Glassella by differences in carapace margins and ridges, male pleon outline, and the shape of the GP.

Reproductive aspects of Grapsus grapsus (Decapoda: Grapsidae) on islands of the southeastern Gulf of California / Aspectos reproductivos de Grapsus grapsus (Decapoda: Grapsidae) en islas del sureste del Golfo de California

ABSTRACT Objective. The sex ratio, proportion of ovigerous females, length at sexual maturity and fecundity of Grapsus grapsus crabs in the Lobos, Venados and Pajaros islands (southeastern Gulf of California) were analyzed. Materials and methods. Sampling was conducted monthly between March 2011 and February 2012, during the night at low tide. Thirty crabs were collected in a quadrant (25 m2) at each sampling site on each island. cw (mm) and w (g) were determined. The sex ratio and size at sexual maturity (cw50%) were estimated, and for ovigerous females, embryonic stages and fecundity (gravimetric method) were determined. Results. The sex ratio (M:F) was 1:1.3. The average size at sexual maturity (cw50%) was 34.9 mm. The majority of females were ovigerous (71.3%), and 48% of the embryos of ovigerous females were at the red-orange phase. Egg diameter ranged from 1.1 to 5 µm, with an average of 2.05 µm. The mean fecundity was 24339.3 eggs. The maximum and minimum weight of ovigerous females was 69.9 and 15.2 g. Conclusions. The studied characteristics of sex ratio, proportion of ovigerous females, length at sexual maturity and fecundity of G. grapsus, indicate the effective administration and management of this resource in this area.

RESUMEN Objetivo. Se analizó la proporción de sexos, hembras ovígeras, talla de primera madurez sexual y fecundidad del cangrejo roca Grapsus grapsus en islas Lobos, Venados y Pájaros (sureste del Golfo de California). Material y métodos. Los muestreos fueron mensuales entre marzo 2011 y febrero 2012, las colectas fueron nocturnas durante la bajamar, se obtuvieron en un cuadrante (25 m2) por isla 30 organismos al azar, se les determinó el AN (mm) y PT (g). Se estimó la proporción de sexos y talla de primera madurez sexual (AN50%), se analizaron en hembras grávidas, las fases embrionarias y la fecundidad (método gravimétrico). Resultados. La proporción de M:H fue 1:1.3. La talla media de primera madurez fue AN50% 34.9 mm. Es evidente la presencia de hembras ovígeras (71.3%) y todas las fases embrionarias, la fase rojo-naranja fue la mayor representada en 48%. La variación del diámetro del huevo fue 1.1 a 5 µm y el promedio de 3.05 µm. La fecundidad media fue 24339.3 cigotos. El máximo y mínimo peso de hembras ovígeras fue 69.9 y 15.2 g, respectivamente. Conclusiones. Con base a las características biológicas del recurso tales como la proporción de sexos, hembras ovígeras, talla de primera madurez sexual y fecundidad en la población de G. grapsus, representa un efecto favorable en su posterior administración y manejo de este recurso en esta zona.

Redescription of the poorly known pea crab, Pinnixa plectrophoros Glassell, 1935 (Decapoda: Pinnotheridae), from the Gulf of California.

A complete redescription of the pinnotherid crab, Pinnixa plectrophoros Glassell, 1935, is presented. Glassell's original description of P. plectrophoros, although without any accompanying illustrations, includes a series of morphological characteristics that help, to a certain extent, correctly identify the specimens of the species. A detailed examination of the holotype and specimens collected from Bahía Santa María-La Reforma, Sinaloa, in the central Gulf of California, revealed that the species has features, such as spines and tubercles, which were not mentioned in the original description. The original description of Pinnixa plectrophoros by Glassell (1935b) is hereby modified on the basis of the holotype, deposited in the San Diego Natural History Museum (SDNHM) and fresh material from Sinaloa, central Gulf of California, including illustrations and a photograph of color in life. The specimens from Sinaloa correspond to the second record of the species, 870 km southeast of the type locality.

New records and description of two new species of carideans shrimps from Bahía Santa María-La Reforma lagoon, Gulf of California, Mexico (Crustacea, Caridea, Alpheidae and Processidae).

Two new species of the family Alpheidae: Alpheus margaritaesp. n. and Leptalpheus melendezensissp. n. are described from Santa María-La Reforma, coastal lagoon, SE Gulf of California. Alpheus margaritaesp. n. is closely related to A. antepaenultimus and A. mazatlanicus from the Eastern Pacific and to A. chacei from the Western Atlantic, but can be differentiated from these by a combination of characters, especially the morphology of the scaphocerite and the first pereopods. Leptalpheus melendezensissp. n. resembles L. mexicanus but can be easily differentiated because L. melendezensissp. n. has the anterior margin of the carapace broadly rounded and has only one spine on the mesial margin of ischium in the major cheliped, versus an acute rostrum and an unarmed major cheliped. Additionally, a phylogenetic analysis was used to explore the relationships of these two new taxa. These results show that Alpheus margaritaesp. n. and Leptalpheus melendezensissp. n. are indeed related to the species against which we are comparing them, and demonstrate that they can be considered as different species. Additional specimens of Leptalpheus cf. mexicanus, Ambidexter panamensis and A. swifti are recorded for the first time in the Santa María-La Reforma coastal lagoon.

A new species of Leptalpheus Williams, 1965 and new records of L. mexicanus Ríos & Carvacho, 1983 and L. hendrickxi Anker, 2011 (Crustacea: Decapoda: Alpheidae) from the Pacific coast of Mexico.

A new species of Leptalpheus is described from Estero Pérula, Jalisco, on the Pacific coast of Mexico. Leptalpheus corderoae sp. nov. is most similar to Leptalpheus azuero Anker, 2011 from Panama and Leptalpheus axianassae Dworschak & Coelho, 1999 from Brazil, differing from both of them by a combination of morphological characters, especially the presence of tubercles on the ventral surface of the major chela palm and pollex. The most common host of L. corderoae sp. nov. at the type locality is the callianassid ghost shrimp Lepidophthalmus bocourti (A. Milne Edwards, 1870). Additional specimens of Leptalpheus mexicanus Ríos & Carvacho, 1983, from Estero de Urías, Sinaloa, are reported and compared to the type material from Río Mulegé, as well as to Leptalpheus bicristatus Anker, 2011 from Panama. Finally, Leptalpheus hendrickxi Anker, 2011 is reported from Mexico for the first time, representing a significant northward range extension of the species. In Estero Pérula, L. hendrickxi lives in burrows of Lepidophthalmus bocourti, sometimes together with L. corderoae sp. nov. 

New records of gonodactylids (Crustacea: Stomatopoda: Gonodactylidae) from the Pacific Coast of Mexico with remarks on the morphology of Neogonodactylus lalibertadensis (Schmitt, 1940).

Eight species of the genus Neogonodactylus have been reported from the eastern Pacific. Up to now, only three of these species have been collected in Mexican waters: Neogonodactylus stanschi (Schmitt, 1940), N. lalibertadensis (Schmitt, 1940), and N. zacae (Manning, 1972). Recent sampling of stomatopods in several localities of the Pacific coast of Mexico, from Mazatlán, in the southwestern Gulf of California, to Oaxaca, allowed us to collect fresh material of these three species and five specimens that agree with the general description of N. lalibertadensis, but with differences in the telson ornamentation and the length of the ophthalmic somite. A close examination of this material and examination of photographs of the holotype led us to establish that it shows slight variation from the typical form. A revised key to the species of Neogonodactylus occurring in the eastern Pacific is provided.

A new species of the caridean shrimp genus Ogyrides Stebbing, 1914 (Decapoda: Ogyrididae) from the eastern tropical Pacific.

The caridean shrimp Ogyrides wickstenae sp. nov. is described from Mazatlán, Pacific coast of Mexico. The new species is most closely related to O. tarazonai Wicksten & Méndez, 1988 and O. hayi Williams, 1981, sharing with them a single spine on the dorsal midline of the carapace. However, the new species can be distinguished from the two allied species by the presence of a single small spine on the second endopodal segment of the third maxilliped and the five-segmented carpus of the second pereopod. A key for the Eastern Pacific species of Ogyrides is provided.