Unique hooks in the male scaled squid Lepidoteuthis grimaldi

Author(s):  
George D. Jackson ◽  
Steve O'Shea

The male scaled squid Lepidoteuthis grimaldii hereby reported for the first time, is equipped with a pair of grossly enlarged sabre-like hooks. These unique hooks, found only on males, are without parallel amongst cephalopods. As a sexually dimorphic character, they are more likely to be involved in reproduction than predation.

Crustaceana ◽  
2021 ◽  
Vol 94 (10) ◽  
pp. 1283-1291
Author(s):  
Kunihiko Izawa

Abstract Triceracolax pagri Izawa, 2021 is redescribed on the basis of specimens of both sexes recovered from the bucco-branchial cavity of the original host, Pagrus major (Temminck & Schlegel, 1843). Both sexes of copepodid IV and the male copepodid III, collected together with the adults, are described for the first time, and sexually dimorphic features in late copepodid stages are discussed.


Zootaxa ◽  
2008 ◽  
Vol 1715 (1) ◽  
pp. 43 ◽  
Author(s):  
RONALD E. WATSON

Stiphodon carisa, n. sp., is described based on material collected in the southernmost watershed in Lampung Province, Sumatra, Indonesia. Stiphodon carisa, n. sp., differs from all other congeners by a combination of characteristics that include having 9 second-dorsal fin rays; 15 pectoral-fin rays; 41–59 premaxillary teeth; predorsal scales sexually dimorphic in number, male with 5–11 and female with 8–16; 25–35 lateral scales; slightly embedded cycloid scales present on belly; male with a triangular-shaped first-dorsal fin with third and/or fourth spines longest but not filamentous and a patch of white fatty tissue posterior to pectoral-fin base; female usually with 5 (4–5) dusky to blackish blotches or spots along lateral midline from second-dorsal fin with usually 4 (3–4) posterior-most spots positioned close together on caudal peduncle, dusky band extending from anterior to eye to upper hypural base usually indistinct posterior to pectoral-fin base, with or without a dusky or black gular blotch; in some females xanthism exists which fades in preservation and in life yellow with orange to bright red markings. Stiphodon semoni is a species common in hill streams of eastern Indonesia and Papua New Guinea and is reported here for the first time from streams entering the Indian Ocean in Lampung Province, Sumatra, Indonesia.


Zootaxa ◽  
2010 ◽  
Vol 2559 (1) ◽  
pp. 36 ◽  
Author(s):  
MATHIAS JASCHHOF ◽  
STEPHAN M. BLANK ◽  
Uwe Kallweit

The adult morphology of male Paramorganiella adventurosa Tonnoir is redescribed on the basis of new material from Tasmania. Details of the male genitalia are described and figured for the first time. The female is described for the first time. Special attention is paid to the clypeus and maxillary palpus, both sexually dimorphic, of which the anatomy is extensively illustrated and discussed with respect to possible function and in the context of palpal modifications found in other Mycetophilidae. Anatomy suggests the palpi of males function as a mechanical tool rather than a probing organ, which is unique among Mycetophilidae and Diptera. Various functional hypotheses are discussed in the context of sexual selection.


Zootaxa ◽  
2009 ◽  
Vol 2325 (1) ◽  
pp. 39-61 ◽  
Author(s):  
MARCELO DUARTE ◽  
ROBERT K. ROBBINS

Details of egg, larval, and pupal morphology are described and illustrated for Calycopis bellera (Hewitson) and C. janeirica (Felder), with a special emphasis on larval chaetotaxy. Wild-caught Calycopis females laid eggs on dead leaves in the laboratory, and the caterpillars successfully completed development on an artificial agar diet to which no leaves were added. Males and females of the sexually dimorphic C. bellera had been previously placed in different genera or different species groups. Calycopis janeirica had been chronically misidentified (and misspelled C. jeneirica). Males and females of this species appear to be correctly associated for the first time. Whereas C. bellera has five larval instars—as reported previously for C. caulonia—C. janeirica has four. Morphological characters of the immatures of C. bellera and C. janeirica are summarized in a table and compared with those of other reared Calycopis species.


Fossil Record ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Andris Bukejs ◽  
Jan Bezděk ◽  
Vitalii I. Alekseev ◽  
Kristaps Kairišs ◽  
Ryan C. McKellar

Abstract. A male representative of the extinct species Calomicrus eocenicus Bukejs et Bezděk, 2014 (Chrysomelidae: Galerucinae) is found and described for the first time from Eocene Baltic amber using X-ray microtomography. The aedeagus is well preserved within the body cavity of the specimen, and it is illustrated in detail. This fossil species exhibits distinct sexual dimorphism: the male has a smaller total body size, as well as a copula-adapted modification in abdominal ventrite 5 (apical margin deeply trilobed, with round medial fovea present); meanwhile the female is larger in body size and has a simple abdominal ventrite 5 (without fovea, non-incised and widely rounded apically). Similar sexually dimorphic characters are typical for extant members of the tribe Luperini, and this report is the first time that they are described in an Eocene species. The known sexually dimorphic characters present in Coleoptera within Eocene Baltic amber are briefly discussed.


2013 ◽  
Vol 15 (2) ◽  
pp. 313 ◽  
Author(s):  
C. PORCU ◽  
M. F. MARONGIU ◽  
M. C. FOLLESA ◽  
A. BELLODI ◽  
A. MULAS ◽  
...  

In this paper, the reproductive biology of the velvet belly lanternshark Etmopterus spinax was analyzed in Sardinian waters (central western Mediterranean). This species was sexually dimorphic with females growing to a larger size than males. Marked sexual dimorphism in size was also observed along the vertical gradient. Histological analysis of gonads was very useful in assigning macroscopical maturity stages. The investigation on the microstructure of oviducal gland (OG) highlighted four morphofunctional zones with mucous and/or proteic secretions according to the zone and to their specific functions and development. Sperm in the OG was found for the first time in E. spinax. The localization of sperm storage tubules deeper in OG suggested long-term sperm storage, which is in agreement with the long reproductive cycle described. This species matured late, specifically at 80.7% and 79% at the maximum observed size for females and males respectively. Mature specimens were found throughout the year with pregnant females observed in winter and autumn. A low fecundity was observed with a mean ovarian fecundity of 16.5 mature follicles.


Zootaxa ◽  
2012 ◽  
Vol 3255 (1) ◽  
pp. 52 ◽  
Author(s):  
BJARTE H. JORDAL

A new species of Phrixosoma from Tanzania is described and illustrated. This is a unique species for the genus in havinga strongly concave female frons. Several characters are described for the first time for this genus, including male andfemale genitalia, mouthparts, thoracic sutures, and several overlooked features of the mesoand metatibiae and sternal processes.


Zootaxa ◽  
2016 ◽  
Vol 4214 (1) ◽  
pp. 1 ◽  
Author(s):  
ZACHARY M. PORTMAN ◽  
JOHN L. NEFF ◽  
TERRY GRISWOLD

Perdita subgenus Heteroperdita Timberlake, a distinctive subgenus of 22 species from the southwestern United States and adjacent Mexico, all specialists on Tiquilia (Boraginaceae), is revised. Nine new species are described: Perdita (Heteroperdita) desdemona Portman, sp. n., P. (H.) exusta Portman & Griswold, sp. n., P. (H.) hippolyta Portman & Griswold, sp. n. (male previously incorrectly described as P. pilonotata Timberlake), P. (H.) hooki Portman & Neff, sp. n., P. (H.) nuttalliae Portman, sp. n., P. (H.) prodigiosa Portman & Griswold, sp. n., P. (H.) sycorax Portman, sp. n., P. (H.) titania Portman & Griswold, sp. n., and P. (H.) yanegai Portman, sp. n. The following sexes are associated and described for the first time: the male of P. (H.) frontalis Timberlake, 1968, the female of P. (H.) optiva Timberlake, 1954, and the true male of P. (H.) pilonotata Timberlake, 1980. Perdita (H.) fasciatella Timberlake, 1980 is proposed as a junior synonym of P. (H.) sexfasciata Timberlake, 1954. A neotype is designated for P. (H.) pilonotata Timberlake, 1980. Two species in particular, P. prodigiosa and P. pilonotata, are sexually dimorphic with distinctive ant-like males. Information is presented on floral relationships, phenology, and geographic distribution. Identification keys for males and females are provided. 


Author(s):  
Axel Hungerbühler ◽  
Bill Mueller ◽  
Sankar Chatterjee ◽  
Douglas P. Cunningham

ABSTRACTThe skull anatomy of a new species of the phytosaurMachaeroprosopusis described for the first time on the basis of two specimens from the Upper Triassic Cooper Canyon Formation of Texas. Additional information is provided by a third specimen referred toMachaeroprosopussp. A paranasal bone, an additional paired element of the narial region, is identified. Important new data are presented for the braincase, including the morphology of the epipterygoid and presphenoid, an anterior process of the prootic, an anteroventral process of the laterosphenoid, and a parasphenoid process.Machaeroprosopus lottorumn. sp. is characterised by four apomorphies: a supratemporal fenestra closed on the skull roof with bevelled anterior rim, a comparatively short squamosal, a flat and rugose narial rim, and medially extended palatines that come close to form an ossified secondary palate. With respect to the supratemporal fenestra, the supraoccipital–parietal complex and several features of the squamosal,Machaeroprosopus lottorumn. sp. bridges the morphological gap between species previously referred to the generaPseudopalatusandRedondasaurus. A parsimony analysis of known species ofMachaeroprosopussupports the hypothesis that the development of the rostral crest inMachaeroprosopusis a sexually dimorphic feature, and questions the validity of the genusRedondasaurus. Consequently,Redondasaurusis here considered a junior synonym ofMachaeroprosopus.


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 165
Author(s):  
Seyed Ehsan Mousavi ◽  
G. John Purser ◽  
Jawahar G. Patil

In fish, little is known about sex-specific differences in physiology and performance of the heart and whether these differences manifest during development. Here for the first time, the sex-specific heart rates during embryogenesis of Gambusia holbrooki, from the onset of the heart rates (HRs) to just prior to parturition, was investigated using light cardiogram. The genetic sex of the embryos was post-verified using a sex-specific genetic marker. Results reveal that heart rates and resting time significantly increase (p < 0.05) with progressive embryonic development. Furthermore, both ventricular and atrial frequencies of female embryos were significantly higher (p < 0.05) than those of their male sibs at the corresponding developmental stages and remained so at all later developmental stages (p < 0.05). In concurrence, the heart rate and ventricular size of the adult females were also significantly (p < 0.05) higher and larger respectively than those of males. Collectively, the results suggest that the cardiac sex-dimorphism manifests as early as late-organogenesis and persists through adulthood in this species. These findings suggest that the cardiac measurements can be employed to non-invasively sex the developing embryos, well in advance of when their phenotypic sex is discernible. In addition, G. holbrooki could serve as a better model to study comparative vertebrate cardiovascular development as well as to investigate anthropogenic and climatic impacts on heart physiology of this species, that may be sex influenced.


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