Functional morphology of the male reproductive system in Callichirus major (Crustacea: Decapoda: Axiidea): Evidence of oocytes in the gonad

Abstract

Resumo: Callichirus major pertence à ordem Decapoda e família Callianassidae, sendo uma espécie que habita a região interdial de ecossistemas praianos, sendo amplamente capturada para utilização como isca viva para pesca. O presente estudo objetivou descrever morfologicamente o processo espermatogênico nesta espécie de crustáceo, com a finalidade de entender melhor a sua biologia reprodutiva. Os animais, coletados ao longo da Praia do Corujão, em Piúma/ES, foram triados e, em laboratório, tiveram suas gônadas masculinas dissecadas e submetidas ao processamento histológico de rotina. As células germinativas foram classificadas em: Espermatogônia (SPG); Espermatócito I e II (SPTCI, SPTCII); Espermátide inicial e final (EI, EF) e Espermatozoide (SPZ). Células acessórias também estiverem presentes, possuindo núcleo esférico ou triangular, distribuídas na periferia e entre a linhagem germinativa no lóbulo gonadal. Baseado nas observações microscópicas foi possível constatar que esta espécie possui a espermatogênese assincrônica, indicando que a reprodução pode ocorrer durante o ano todo.

Morphological study for understanding the sexual pattern in ghost shrimp Callichirus major (Crustacea: Axiidea)

“…It has been reported in the literature that species with this cryptic lifestyle can present a low population density in their burrows ( C. major = 6.07 galleries/m 2 ) and may display characteristics of intersexuality and hermaphroditism (Almeida & Buckup, ; Botter‐Carvalho, Santos, & Carvalho, ; Kang et al, ; Nanri et al, ; Oliveira et al, ; Rudolph, ; Rudolph & Almeida, ; Rudolph & Verdi, ; Silva‐Castiglioni et al, ). In addition, the occurrence of these characteristics in genus Callichirus is described by Hernáez Bové () and Souza et al () for C. seilacheri and C. major , respectively. However, according to Baeza (), the low density condition does not appear to be the main promoter of the development of a hermaphrodite sexual pattern in species of the genus Lysmata and other carideans.…”

“…In the area close to the posterior (ovarian) region, oogonia and a small number of spermatozoa could also be noted in the lumen of the tubule (Figure d). The cells of the male and female germ lines were identified according to classification proposed by Souza, Braga, López‐Greco, and Nunes (), Souza et al (). The individuals in initial gonadal development presented oocytes at an early developmental stage (oogonia and previtellogenic oocytes), whereas those presenting developed gonads had these cells in an advanced stage of maturation (oocytes in late vitellogenesis and mature), indicating that maturation in the ovarian region coexists with gonadal maturation.…”

“…Recently, Souza, Braga, López‐Greco, and Nunes () described the gonadal structure of C. major , pointing out the presence of oocytes in males throughout their entire gonadal ontogeny. Oliveira, Costa‐Souza, Guimarães, Almeida, and Baeza () reported observations on the sexual pattern of the caridean Salmoneus carvachoi , which displays a lifestyle similar to that of C. major , indicating a possible example of simultaneous hermaphroditism for this species.…”

La efectividad de una ley de protección al servicio de la conservación de un recurso marino: El ejemplo del camarón fantasma Callichirus major (Decapoda, Callianassidae) de la costa de Brasil

“…Pandalus jordani Rathbun, 1902, Solenocera membranacea (Risso, 1816]. Estudios recientes indican que los machos de C. major poseen gónadas con una sección testicular y ovárica (Souza et al, 2017), mientras que las hembras presentan aberturas genitales extras sobre las coxas del quinto par de pereiópodos, tal cual como sucede en los machos (J. P. P. Rio, datos no publicados). Estos antecedentes, sugieren que la distribución de la proporción sexual por la clase de tamaño de C. major observada en la playa de Gonzaga podría esconder una estrategia de cambio de sexo, tal como ocurre en muchos camarones Caridea (Bauer, 2004).…”

A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support

“…Callichirus kraussi is here removed to its own genus, Kraussillichirus, on genetic evidence (Robles et al, in press) and uropodal endopods more typical of the family. Species of Callichirus may be functional hermaphrodites with some or all females having male gonopores (Souza et al, 2017(Souza et al, , 2018 Corallianassa Manning, 1987 Corallianassa Manning, 1987: 392-394.-Poore, 2004: 184.-Ngoc-Ho, 2005: 71.-Komai et al, 2015.…”