ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES)

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  ECOLOGICAL NICHE MODELS BY TITYUS SERRULATUS LUTZ & MELLO, 1922 AND TITYUS STIGMURUS (THORELL, 1876) (ARACHNIDA: SCORPIONES) Summary Scorpions are venomous animals with high plasticity and can serve as models for biogeographical, natural history, and evolutionary studies. Ecological niche modeling can help in understanding essential characteristics of the geographic distribution of species, as well as allowing the prediction of future distribution patterns. Our objective was to model the ecological niche of the scorpion species *Tityus serrulatus * and *Tityus stigmurus* , as well as to identify the variables that influence their distribution in different biomes and their range limits in the Amazon, Caatinga, and Cerrado biomes. Data were obtained from 12 Brazilian arachnological collections. Bioclimatic variables were obtained from the WorldClim database, and niche modeling was implemented using the Maximum Entropy algorithm. The results showed that the Atlantic Forest bio...

Reproductive phenology of an opilionid species maturing in early summer, Himalphalangium spinulatum, showing evidence of protogyny (Opiliones: Eupnoi: Phalangiidae)

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Reproductive phenology of an opilionid species maturing in early summer, Himalphalangium spinulatum, showing evidence of protogyny (Opiliones: Eupnoi: Phalangiidae)

Abstract

The reproductive phenology of Himalphalangium spinulatum (Roewer, 1911) (Eupnoi: Phalangiidae), which overwinter as juveniles and mature in early summer, was surveyed at a riparian forest on the Sendai River, Tottori City, Honshu, Japan. Females became adults about 3–4 days earlier than males. The body weight of females and males and the number of mature eggs retained in females were highest at the age about a week after the final molting, suggesting a shorter time is needed to commence mating and oviposition in this species. This might be the reason for the shorter time lag in maturation between females and males in this species compared to other species of protogynous harvestmen.

Nobuo Tsurusaki, Minako Kawaguchi, Yamato Funakura, Toru Matsumoto "Reproductive phenology of an opilionid species maturing in early summer, Himalphalangium spinulatum, showing evidence of protogyny (Opiliones: Eupnoi: Phalangiidae)," The Journal of Arachnology, 53(1), 13-19, (19 May 2025)